327 mods

Hi all, I'm Rob from Australia. I'm about to take delivery of a customised 1970 Holden (GM) Utility (pick up). It's powered by a Chev 327 that transmits its torque through a TH350 trannie and a v8 3.08:1 ratio banjo diff that so far, has stood up well. I'm a 39y/o 'A' grade mechanic who's finally getting his v8. This is what I want to know guys. What mods have you guys done to these engines that have been really effective without you having to take out a mortgage to obtain? I don't know yet if the heads are the double hump (or whatever u call em') type, what compression it has or what cam it has. It has a Holley carb of unknown CFM. I'm willing to change the camshaft, rockers (roller tipped only), valve springs and intake manifold. I'd also give the heads a 3 angle valve job, raise the compression, clean up the ports whilst matching them to the intake manifold ports. My friend has offered me a Camaro alloy intake (the current one is iron) - are these any good or should I fit an E/B Performer one? It has the standard cast exhaust manifolds, which I'd like to keep as I like their appearance and they fit the tight engine bay quite neatly. Has anyone been able to get respectable performance gains while still retaining these cast headers? The rest of the exhaust system appears to be free flowing as the twin outlets let it be known that there's a Chevy 8 under the hood. I don't know if the exhaust has a balance pipe fitted, but get the feeling it does'nt due to the beat of the note. The engine pulls like a demon off the line but becomes real weazy around 4,000rpm - almost as if the cam is advanced. I want the engine to have real presence so I don't mind it idling with a little anger. I'd prefer to retain the standard torque converter but would change to a higher stall type if needed. Again I'd like it take off well but more importantly, it needs to get up and boogie as the revs climb. I don't want to push it beyond 5,500 or maybe 6,000rpm as I don't want to touch the bottom end $. So, if any of you have been in a similar situation and are willing to share your secrets with an Aussie (pronounced ozzie) then please, let Rob know.
Or maybe even put me onto a site that caters for my questions. Have any of you seen the retro dress up kits for the S/B offered by proformparts? I gotta get that kit. Bloody awesome and not a bit of chrome to be seen! (yeah, yeah, I know I show my age fargin). One more thing. Do you think I should stick with the TH350? Or should I update to a TH700. I've heard the 4speeders are a little on the weak side. If so, what can be done to beef them up. I've been told to use a vette' servo as well as a transgo shift kit. Thanks for putting up with my huge ask. I hope your day is a good one. Cheers! Rob

Welcome Rob, looks like you've already gotten into the swing and have been helpful. Fargin? Ya gotta love the www!

To perform, these engines gotta breath. Running out of oomph at 4k with a 3.08 sounds like you've got a rag caught in it (figuratively of course). Probably you need to figure out the heads, and carb, at least, before really pinning it down. You could be right about the cam being off a bit, or it could simply be timing, or the advance isn't functioning correctly. Carb should be 600-650 cfm if it's a mild cam, and "small" heads. I've gone to 750 but the engine really needs to move air to do that.

Your desire to keep the iron manifolds may fit the compartment restrictions, but they could impede your ability to improve the breathing. You didn't say whether they were the logs, or the ram horns. Ram horns flow slightly better, and the fuelie Vette versions have a larger outlet. Otherwise you may have to consider block hugger types, especially the "flat" collector Hookers.

You didn't state which model Camaro intake it was, but the factory manifolds were pretty good in their day. The older style Performer was essentially the same manifold (P/N 2101 I think?) but the newer ones are a slight improvement. Their newer airgap model might be better if you don't need any heat to the plenum for all around operation.

As for the trans, the 350, especially with the 3.08, should fit just fine. They'll handle all the torque a 327 will dish, and I agree with the Transgo over. say a B&M, for shift improvement. The extra gear in the 700 would be good if you were planning to drop the gear ratio into the 4's. It was the early models of the 700 that gave them a bad name, as well as the 200's that came about in the same era. The later 700's were corrected by GM on the fly, and have stood up well. Raising the stall is popular (though sometimes a boy racer thing), but really only has advantages if the car is pretty light, or you really need to get the launch into the power band.

Thankyou Bob for at least giving me a logical and realistic reply. As I said, I don't won't to outlay big bucks (no blower, 6:1 pistons, twin predators, steel crank or wateva fargin alright!). Yes I'd be doing the basic preliminaries upon delivery, like checking its ignition advance. I'm also a little suspect that the carb is having a major lean out at the upper rev range. I can check all these things at work as I have access to a 4 gas anilyser scope but, unfortunately no rollers. At this stage I don't know what kind of Camaro intake or even what kind of exhaust headers it has. Are the ram horns the ones that look like 2 eyebrows? I get the feeling it may have the logs, dam it! My friend James is also giving me his Chevy hot rod engine mod book that should maybe help identify a few things for me. Again, thankyou Bob and look forward to more contact from you and Streets fargin. Rob

Eyebrows? Yeah, that'll work for a visual! Just watch those four "eyes", they can have a bite?!!;)

High. It's me again. I've noticed there's been about 45 viewings of my post but only two guys offering help. Where's that good ol' American spirit gone? Don't you want to help? Or do you think I should just gamble on matching individual parts and end up with an unsatisfactory result. Yes, I'm a mechanic. But I don't play around with engines trying this and that - that's real experience I hav'nt had and that cannot be substituted with just books. So, even if you're not so sure, tell me what you know or what's under you hood and what works. I'm all ears. Show me that you guys are willing to help. Rob

High(?) Rob.
If you scroll down the home page you'll see that there are more guests than members reading the posts. You have to join to reply. I dont have a lot of experience with modifying engines. I'm usually satisfied with the performance of a stock engine. The last Chevy engine I rebuilt I used an Edelbrock performer plus intake manifold (p/n 2101) and the performer plus camshaft (p/n 2102). I used a pair of block hugger headers. You can find these parts in the Summit catalog. They have a website at www.summitracing.com and they'll ship to Aussieland. I think their catalog is free but they may charge for postage if you're not in the states.
You still haven't given us the transalation for fargin but maybe it's something you shouldn't put on a family oriented website.
AL

Club327, I just saw your post this morning, didn't have time to reply to it then, But when I swapped out my 350 for 327 in my camaro, I used the stock heads that came with the engine and the intake from the 350 I was pulling out of it, Engine ran great, had enough power for me, Not quite sure what exactly it was running as far as HP, but I do know I could break a brand new set of tires loose taking off, and from 1st to 2nd, and I do know that I could do a "brake stand" until I couldn't see from all the smoke. I guess it all depends on what you want and how much you are willing to spend. Me I would look more at going as much stock as possible for a daily driver, if you want one for racing then you will need to look at the pocketbook to see what you can get.
But I am a firm believer in stock, after all GM has more money than me to test what works.

Rob, just a thought here. It could be that some folks are waiting for an update from you since you indicated you weren't sure of your base line condition. My thoughts were predicated on some broad generalities for that same reason. Once you've defined what hardware you do have, and have used your skill to refine the tune for what's there now, there would be a better chance to make meaningful suggestions. Especially when your budget comes into play. As an example, on the 327 I currently have I've got aluminum heads, done that way so I could push the compression ratio to 10 to 1. But you may not want to toss that kind of cash at yours once you have it in possession.

BTW, loved your auto trans function post, good job!

Hi (high? woops). Thanx to all of you for your replies. It's trully appreciated. Like I said, I'm all ears regardless of how inexperienced any of you are. Al, that's the kind of track I want to go down, ie. E/B performer 2 manifold and cam set - something like that. Now these block hugger headers, they sound good mate! Are they compact and do they offer improved upper RPM breathing and scavanging? Let me now how any of you went with these please. Streets, I did ask to keep it simple and cost effective - and what did you recommend me to do? You said fit a GMC 89-2 blower, twin predators, 6:1 pistons and so on. No one will take you seriously with those kind of comments. I think you show your youth and I admire you enthusiasm, so don't be offended with what I said. You obviously know quite a lot and I value any constructive help you can give. Rob

Streets, that's 58 in dog years, right?:3dSMILE:

Rob here's a pic of the "flat" collector, block huggers I referred to. Probably too short to have much scavenging effect, though a proper head pipe could help a wee bit. They're more for fit, though the smoothness of the tubing will help flow some. Get them ceramic coated in and out and they perform even better.

What heads do you have???Do they have a little sybol cast into them that looks like a camels back,two humps on a block and no acsesory bolt holes???If not really we need to know what valves ya got in your heads,if ya got little 1.72 valves and we recomend a cam thinking ya got 1.94 or 2.02 double humps you'll end up with a torqueless pig that also can't rev.Take a valve cover off and look at the last three #s of the casting # ,look them up at www.mortec.com that should tell ya a little.
As for compression I dunno.But if they are no-double humps I would assume an 8.5:1 ratio(as this is a typical non-Hipo ratio) for cam selection and 9.5:1 with double humps(if they are origanal to the motor).
I would say on the intake if the Z28 intake is a aluminum and has no EGR valve use it,if not get a performer eddy.
As for Ramshorns etc....I wouldn't use anything less than blockhugger headers.For street I would keep any headers in the 1 5/8 pimary range any bigger you give up lowend torque.
For a street motor with 3.08s I say the TH350 will fit the bill great.The only reason I would use a TH700r4 or TH2004r is if I had a real nasty gear that needs to be calmed down on the highway.These trannys are expensive in comparison to the TH350.

Thankyou Bob for the pic. I did'nt realise those headers were going to be of the tubular type and was surprised with what I saw. They look real compact and although there's no obvious scavange effect with the design, they appear to be able flow the exhaust in the right direction - away from each other and downwards. That's a lot better than the conflict that would be occuring inside those logs (hey I'm learning fast!). Do you really think that ceramic coating them makes a noticeable difference? I'm a little sceptical, but am curious just the same. Do those headers have a standard flat flange to connect the pipes with? Or are they a slip fit? Thanks again Bob. And if any of you find anymore spelling or gramma errors, please refrain from correcting me. I never realised I was sitting for some kind of English test! He he. Hey Streets, whatever kind of solvent you're sniffing could you let me know what it is? Coz when I'm gonna be a 58y/o like you, I wanna have the same outlook! Shoemaker, I'll be picking the car up this afternoon as it's not raining anymore and I'm choosing to keep it out of the rain. It's gonna be my occasional fling car! Right now it's 10:14 am. So you guys would be in la la land catching some ZZZZ's, as your time is currently 3:29am. See, we're not as backwards as you guys may think. I'll do a quick check over with fingers crossed, for the double hump markings on the heads. Those tips u gave me for the numbers found when the rockers are removed are going to be real helpfull. Did'nt know that one! So you also agree about the block huggers hey? Good, looks like I can so far settle on one thing. Bye for now and have a good weekend to all my friends here. Rob

Rob, if it's going to be your "fling car", as a retread, I'd advise you don't let your wife catch on!:D

The headers have a standard (for us anyway) three inch, flat flange, three bolt collector. Most often they come with a matching reducer to go down to 2 1/2". Yes, I'm a firm believer in the ceramic coating. It prolongs the life of the header by significantly inhibiting corrosion. It retains the heat within the header better, giving just a modicum of performance increase, but more importantly, lowers under hood temps. Smoothes the inside of the tubing even more for better flow, and they look better.

To give you a leg up, here's a link to a head I.D. chart, so you don't have to deal with verbal pictures. http://www.angelfire.com/tx5/randysr...Headguide.html

As someone who probably wouldn't have gotten out of high school unless they threw me out, I don't play the english teacher much. It's just that my brain sees something out of place and "blips" for a moment. But it's really no big deal in the long run.

Hey Bob, you're a gem. I looked up that site and saw plenty of info and stuff. My heads are not the double humps. They have a short and a long squared off shapes that dont really match with anything there. There's no accessory holes in the heads either. Will take a look at the numbers under the rocker covers to crossmatch them with the charts. A retread? Does that mean you've been married twice? Well, my wife thought it would be a good idea if I just packed up and leave early last year. Very easy for them to do over here, as they'd be earning $500 - $800 a week net, through child welfare as well as from child maintenance from the X hubbies. We've got big probs over here, sorry to say - lots of broken families. Not my idea of a good start to life.
So this car is well and trully my new love (when I'm actually not with the female variety) and I'm absolutely over the moon over it. Someone's spent over $20,000 on this beast and I got it for $6000 (about $4600 US). Every body bolt and washer are stainless steel - the bolts are of the unbreako type. Ever body part has been attended to in detail with TLC including the underside. The interior is fully retrimmed including the hood lining and sun visors - this is stuff that I don't usually want to tackle as I'm impatient, so it's a real bonus. I made a few errors when I first road tested it Bob. That weezy top end performance I was telling you about is actually the transition stage between the carb primaries and secondaries. I never actually got out of the primary stage. There seems to be a 500rpm hole before the secondaries become effective. I can live with it for now as it really lifts its skirt and howls like I was always expecting it to do. Gotta love you yanks. It has rams horns manifolds which I'm quite content to keep for now. The other thing is the diff ratio. I get the feeling it may be a 3.55 or lower ratio. I'm always wanting to shift into a higher gear when at cruising speeds. So who nows. maybe a TH700 maybe just the ticket hey? I'll keep you posted about the heads and will try to send a picture if you're interested. Cheers!

Looks like I need a stronger spring to slow down the opening of the vacuum secondaries. I'll get a kit with the various springs to try. The head casting number is 3911032 - it's a Canadian casting. The only info I can get is that it's for a 307 and 327, used in trucks and has either 67cc or 70cc chambers. No mention of valves sizes. What do you guys know about these?

i just noticed this post but friend has 68 327, roller cam, 461 heads with 2 05 1.6 valves (expensive to do on iron heads) holley 750 double pumper, all msd ignition which i would recommend, headers, good rear end 4 10 gears, turbo 350, 3500 stall, edelbrock victor jr intake, motor runs real strong, all street car and eats almost any car around, revs to an easy 7000 rpms 327s are known for that, i would recommend bigger valved heads but those are just some options he has done, in 86 monte carlo and motor flies, good choice with the 327. ask for that streets guy, blower sounds great but dents the wallet, and from what i read i wont say anything bad cause he knows way more than i do, good luck.

Wow, 1.72 and 1.50 sized valves huh. That would certainly explain the stump pulling torque off the line. Oh well, looks like I'd better do some shopping hey. Mind you, it still really scoots along as the body's quite light as it was mainly designed for 6cyl applications, with the v8 being called upon for the prestige and performance models. If I can get my hands on a decent set of heads then i'd be in business. What compression ratio does 70cc chambers give with stock pistons? 9:1? I've yet to hear any detonation and am using lead replacement super petrol (gasoline, benzina, whatever) which has an octane rating of 98RON. What fuel are you guys forced to use these days? Do you still have lead additives in your super fuel? What compression is ok for street use. From what I've read, 9.5:1 to 10:1 seems to be the safe limit before octane booster is used. Streets - I too have noticed that you've past the 1000 post milestone. I reckon a gold watch is in order. Anyway, I hope things improve for you. Again, thanks to all for your help. This post will keep on going until I've had my fill so get used to it!

Ya know Rob, you're getting to be almost as much of a trouble maker as Brisco!!:p

To completely deal with the octane thing would probably take another one of those two part posts (each post is limited to 10,000 characters). You snuck in the RON on your 98 there, which is a term not often used in this country. It stands for Research Octane Number, and is a meaningful qualifier, but only if understood by the reader. Which in this country is not very common. We have a rating number on our pumps that is an average of two rating methods, the Research number as above, and what's referred to as Motor Octane Number (MON). If you were to look at the sticker on a pump here there would be a formula in tiny print at the bottom that shows R + M/2. Meaning, Research Octane Number plus Motor Octane Number divided by 2 = the average of the two tests. The RON and MON are two tests run on the same sample of fuel, the MON being the more severe and yeilding a smaller number. The typical spread between the two is 8-10. So a 93 rated fuel at our pumps would be a 97-98 RON fuel. We had a lot of understanding issues, particularly in the mid '70's to early '80's, because the vehicle manufacturers were using the engineering approach in their owner manuals and specifying the RON level numbers, but the stations were required by Federal law to post the R+M/2, which, as you can see, is a lower number. Poor consumers were going nuts, at least the few that read the manual, and of course the oil companies were blamed. (Government dodged the bullet again). In time the manufacturers revised their manuals bringing peace and harmony across the land!

Your 98 RON is way more octane than the 8.6 to 1 that Richard calculated requires. You probably wouldn't have any ping with a 93 RON fuel, or whatever your "Regular" grade is. As for your lead question, no, all our "street" fuels are unleaded now. A few brands of racing gasoline still have lead, but there are also unleaded, high octane, racing gasolines out there. In most cases the engine doesn't care if there's lead in there or not. Many folks here, and perhaps there, fear exhaust valve recession (if they're rational), and some fear total annilation of their engine (if they're irrational) if they use unleaded fuel. While exhaust valve recession is a POSSIBILITY with the use of pre-'72 cylinder heads (this country, I don't know about yours), it usually only occurs in severe use e.g. racing, trailer towing, or any other regime that causes high, sustained, cylinder head temps.

And BTW, I don't wear a watch, so just send the money!:LOL:

Bob, if you like, you can ignore me, but I won't go away (trouble maker?). He he! Give me your postal address so I can send you a check to the value of one gold watch - which happens to be worth $427.55 Aus. That's $2.75 when converted to US currency! Better get me that address before I change my mind.. Rob**)

Now I want slightly different help. I've seen those under header ignition wires (refered to as high tension leads over here) and want to get them for my ute. I love the clean engine look and hate the sight of any kind of excessive wiring. I've looked at summit racing and jegs, etc. They are very limited in that line of stock. But there real question is, what clips and brackets (kit?) are available to have the wires kept firmly in place away from the hot manifolds. Would still be with those sexy rams horns (woof woof). Hey Bobby Dazzler, where've you've been lately huh? I'm about to start cleaning up the wiring under the dash of my pick up. It's a real mess and is a fireball waiting to happen. I've just secured the battery + cable loom away from the manifolds - found the several layers of insulation had melted through as the loom was hard against the manifolds in 2 locations . Also had to rewire the burnt starter solanoid wire and temp sender wire for the same reason. Looks like a lot of people can throw expensive parts together to make a cool street machine. But time and time again I've seen real ugly and nasty wiring jobs that are just a nightmare to figure out. Being able to do good electrical work is often what seperates the men from the boys. Do you have any ideas on those ignition wires Streets? **)

Rob, gotta dig in the memory bag here, but I seem to recall some of the early '60's Chevs, might have been Corvettes, routed the wires down the back side of the heads and then under to come up below the plugs. You could easily fashion the wires from a cut to length kit, just make sure you have a proper crimper. For the brackets, you might check with Year One, or one of the other Chev "restoration" part suppliers, they may be repopping the brackets that, I think, fastened to bell housing bolts. Once you look at it you should be able to visualize the routing. As for clamping the rest of the wire, I've used some of those nice plastic ones from Mallory for 2,3,&4 wires, Mr. Gasket makes some too, but somewhat lower quality. I've taken some scrap sheetmetal and cut some brackets of my own and fastened them to the clamps using the through screw that holds the clamp/separator together.

I hear ya' on the under dash wiring. A few years ago I had a '40 Ford deluxe coupe that some hack had wired. When I finally got tired of it I pulled the dash one day, and started cuttin'. The clown had used good wire, and the fuse panel wasn't too bad, it's just that he left too much wire there, and just wadded it in.:rolleyes: After some judicious shortening, reterminaling, and routing it turned out very neat. Really only took about four hours, but some folks just don't have the patience I guess.