A little help please

Looking for input. Finished the 402 top to bottom from my 1971 SS 396 Camaro:
.030 over
10/10 grind on the crank
reconditioned rods with ARP bolts
Machine work and hyper pistons to 9.5:1 CR
Comp Cam Xtreme Energy (sorry Pat) 218/224 with .504/.510 lift 110LSA
New springs for cam
Qjet
Pertronix
Stock intake
Car is M22 4-speed with 3:42 Posi rear end

Engine is back in the car and I'm getting ready to do the fine tuning on the dyno but am thinking about adding headers. Before I spend the money for the dyno, what header should I use? And what can I expect to gain?

Thanks much for your thoughts and experience!

The short answer is yes, headers will get you some horsepower. Remember that the exhaust system is the entire unit from exhaust valve to tailpipe. The most benefit will occur if you can remove other restrictions, i.e., use a good free flow muffler (Flowmaster or similar). I think you can conservatively look for 20-30 horsepower with a complete free flowing system installed by a competent muffler shop. I like 2-½ pipe (others will suggest you go larger) with a cross over as shown below.

If I were you and had just completed that engine, I’d think about ceramic coated headers like Hooker 2217 or similar. They’re made for big block Camaro applications and my experience with Hooker is that they fit well. Bear in mind the ceramic coated headers are pricey ($750 from Summit!) – but they will last long after standard heavy tube steel headers no matter how well you prep and paint them.

As a side note – another obvious area (from your picture) to pick up a couple ponies and increase reliability would be to install a GM HEI distributor and use a Mallory or MSD coil.

Looks great Scottyo – let us know how you progress

Regards and Welcome to CHR
Glenn

Sorry - didn't see your Pertronix (I still like the HEI):3dSMILE:

I wouldn't - if you have those manifolds in the pic. They are very efficient, just run some big toobs to them and let 'em go. Can the ignition and go full MSD - millions have and did you ever, ever hear of anybody shitcanning MSd to go with pertronix or hei?
Nice car, you're going to have a ball with it.

Great job on the engine man, it looks awesome. In my opinion, if you plan on some more performance than get the headers. You will see improvements everywhere on horsepower and torque. I don't think you need huge ones, maybe 1 3/4 or 2 in primaries with 3 inch collectors, but, if you do you get headers you can't put painted ones on a motor that is that clean. Go ceramic if you can or save up for em', I found a pair of Hooker comp. ceramic coated for my 84' shortwide for $200 on Craigslist. They are out there but if you have the money I think they can be had for cheaper that $700. Any name brand header is going to be good, Hooker, Hedman, even the Summit brand would be good if they offer a ceramic coating. Thumbs up man, you should post pics of the car when its done. P.S. if you're going to dyno tune I would wait til' you get the headers because it could throw off you're tune a little because it will be more efficient.

check these out from Summit.


http://www.summitracing.com/parts/HOK-2455-1HKR/

Thanks guys. I have a mandrel bent 2 1/2 system already installed with H pipe and Flowmaster 40's. I used Dynatech clamps to prep it for a change to headers if I decide to go that way.

You're dialed!

I like the Hooker 2455 as well and they're a bunch less money!

It's an all numbers car so I was going for the "factory" look. As you can see, I prepared the exhaust system for headers and if I can pick up enough performance gains I will slap em on cause I can switch back to "factory" pretty quickly. I have a lift in the garage so I spend an afternoon and I'm done. Just don't know how much I'll gain?

you will pick up some power how much maybe 30+ you have a good ex so your 1/2 way there so you not going to see alot with a cheap set of headers good ones abit more . but over all the iron mainfolds are not to bad the do not leak seal up good ,no burnt spark plug boots . you can re work the iron mainfolds and get them coated there work abit better .looks like your not really street racing it any ways ? there was a guy here in town that like to dress down his bbc with stock valve covers iron ex stock looking stuff

I just took my headers off my 72 monte carlo. It has roughly the same 402 as you scotty. I spent 3 hours on my manifolds by grinding out the air fitting humps inside the port and smoothing out the turns. Knocked off the casting flash as well. I wanted the engine to look stock again as i put the car in shows. I did not notice any difference in performance but the exhaust sounded deeper( better in my opinion). The car ran a 14.38 with headers and 14.44 with the manifolds. I'll take the manifolds any day unless you are building real hp, Which you are not because it's a 402. Now i can pull the oil filter off without pulling the driver side header off.

i use to love to beat guys with my boring stock looking bbc with stock valve covers and iron ex .oh did i say that :)

This gets complicated. I'm finding tuned ceramic coated headers in three sizes:

1 3/4" tubes with 3" collector
1 7/8" tubes with 3" collector
2" tubes with 3" collector

Which will work best for my car, as described above, which is primarily street driven with an occasional display of speed (that's what the ticket said) kinda thing?

beautifull looking scotty

Any of the sizes will work good, basically smaller primaries are used to boost lower rpm torque and larger primaries are used to boost upper rpm horsepower. I really don't think there will be enough difference to tell between these three sizes. I would go with the ones you want and can afford, not going to be much difference between em'. I would choose one of the two smaller ones, and if people wonder why you have headers on a numbers matching car, tell em' they were dealer installed!!

Quote:

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Originally Posted by pat mccarthy

i use to love to beat guys with my boring stock looking bbc with stock valve covers and iron ex .oh did i say that :)

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632 cubic inches will make up for a multitude of sins.:LOL:

Quote:

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Originally Posted by scottyo

This gets complicated. I'm finding tuned ceramic coated headers in three sizes:

1 3/4" tubes with 3" collector
1 7/8" tubes with 3" collector
2" tubes with 3" collector

Which will work best for my car, as described above, which is primarily street driven with an occasional display of speed (that's what the ticket said) kinda thing?

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well when i built headers i allway built up to a tube size that was a base off hp of the engine for the job.a well built sbc 1 3/4 blown 1.7/8 to 2. bbc never any thing under 2 most all the time 2 1/8 any thing past 500 cid 2 1/4 to 2.3/8 it is better to be abit on the bigger size as it will not be to long when you may want bigger CID and more power so the 17/8 min the 2 would be better if you going bigger on cid

Quote:

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Originally Posted by techinspector1

632 cubic inches will make up for a multitude of sins.:LOL:

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no i never did that on engines like that. the iron logs where on a all iron block 030 454 flat top engine O deck with very few other things in it .that did beat many and lost very few:3dSMILE: when i take the 632 out thats like hunting babby seals i do not hid the big stick i going to hit them with