383 for towing a travel trailer

They headers are already on the truck. Even though I am not ready for the engine overhaul, when I bought the truck last week, the exaust system was in bad shape.(Both exhaust manifolds were cracked and the muffler was blown out). So in order for me to even drive the thing until I am ready to pull the engine, I had to put a complete exhaust system on it.

The truck I have been pulling my trailer with is a Ford f250 extra cab, 3/4 ton with a 351W(210 HP, 315 lbs. of torque). My goal is a Chevy small block with 350+ HP and 400+ lbs of torque at about 3000 RPM.

So if these smaller headers take away 30 lbs of torque. it will just have to do for now.

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Originally Posted by jbright300

They headers are already on the truck. Even though I am not ready for the engine overhaul, when I bought the truck last week, the exaust system was in bad shape.(Both exhaust manifolds were cracked and the muffler was blown out). So in order for me to even drive the thing until I am ready to pull the engine, I had to put a complete exhaust system on it.

The truck I have been pulling my trailer with is a Ford f250 extra cab, 3/4 ton with a 351W(210 HP, 315 lbs. of torque). My goal is a Chevy small block with 350+ HP and 400+ lbs of torque at about 3000 RPM.

So if these smaller headers take away 30 lbs of torque. it will just have to do for now.

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Alrighty then.

What about roller rockers? To get more midrange torque, is there any adavantages to using the 1.6 ratio rockers on both intake and exhaust or on just the intakes?

Full rollers will free up a little power due to reduced friction. In my opinion though, I wouldn't use 1.6's with an Extreme Energy cam like I used for the DynoSim pull. These cams are ground at the maximum lifter rise without the lifter digging into the side of the cam lobe and are already at the max for lifter/lobe pressure in my opinion. Putting more pressure on the lifter/lobe interface would be asking for trouble.

Okay, 1.5's it is. That is just one more piece to the puzzle.

There was a good article in Car Craft that built a budget 383 with Vortec heads(The ones you like) and the numbers are impressive. They give a good parts list too.

http://www.carcraft.com/techarticles...cam_specs.html

This may be a stupid question, but if you haven't either go the new headers or have not installed them, why not send them back to Summit so you get the right ones for your app. I have always found Summit to be very accomodating even when it's been my stupid mistake and not theirs.

They are already on the truck. Unfurtunately, I put them on before I found out that I really needed larger ones. My stupidity, so my loss.

OK, Jeff has PM'd me and is still working through a combination for his grunt motor. Since there is insufficient space to answer on PM (PITA 1000 character limit), I'll post my answer here on the original thread.

Since I can't seem to get Jeff up off the dime to get the correct 1 5/8 or 1 3/4 headers, we'll work with what he has.

Jeff, I would resist the purchase of the Summit intake/carb combination simply because of the manifold. Nothing wrong with a 600 CFM carb for your application, but the low-rise intake they're offering won't cut it. You need to uncork the intake and exhaust to let the motor breathe and the correct intake is an Edelbrock Performer RPM dual-plane, high-rise. Think of it as a Z28 intake. They should never have used "RPM" in the name because this manifold (and others like it) will make more power and torque from idle to 6000 than any other dual-plane intake. Don't like Edelbrock? Fine, use a Weiand Stealth or Professional Products Typhoon. I've seen 7101 (square bore carb) Edelbrocks all over ebay (Ebay Stores) and other places for $149.95. There are also several offerings on ebay right now for used 7101's for a hunnert bucks or less.

For a carb, I'd use the Edelbrock 1405, 600 CFM, manual choke. Never did like automatic chokes, I want to know what the carb is doing at all times. Mount a micro-switch on the choke arm and run it to a small dash light to remind you the choke's on. Here's an offering from the Carb Shop with 2 days left on it. I'd bid a hunnert bucks on it. Item number: 130299766404. Don't like this one, OK, call the Carb Shop and order up whatever you want. Nothing wrong with a rebuilt carb from a reputable rebuilder in my opinion. Then, order up this calibration kit from ebay Summit, Item number: 370179428001 so that you can tune the carb to a gnat's eyelash once you get the motor running and take some plug readings. The item says 1406, it will also fit a 1405. Use this tutorial to tune it.....
http://www.edelbrock.com/automotive_...ers_manual.pdf
I didn't link ebay because the management here doesn't like it and that's cool.

We're gonna use 9.7:1 SCR and the cam I originally suggested, installed advanced 2 degrees. RPM intake, 600 CFM.
http://www.compcams.com/Cam_Specs/Ca...x?csid=85&sb=0

RPM HP TQ
1000 54 284
1500 103 361
2000 147 385
2500 188 394
3000 241 422
3500 286 430
4000 319 419
4500 342 399
5000 348 365
5500 304 290
For you other guys out there building a grunt motor, this combination will make another 15 hp and 22 ft/lbs of torque with 1 5/8 headers.

Those numbers are PERFECT! I will stick with the Edelbrock 7101. I will find one either on ebay or craigs list. As far as the carburetor goes, I am going with a new one. Don't know which one yet, but a new 600 CFM. I will also use the 12-238-2 cam.

The only thing that could really be a fly in the ointment is that the 882 heads on this 1974 2 barrel 350 truck could possibly be 1.72 intake valves. At least that is what some articles that I read say. Most likely they are 1.94, but if they aren't, then I will have to find some that will work.

Hey techinspector1, what version of Dynosim are you using?

Jeff

Hi jbright300,
I wish we had rust free trucks in the Northeast like you guys have. I would love to build a 60-70's pickup without rust.
I sell balanced stroker kits that I would prefer to use a 4 bolt main block (although 2 bolt mains will still work, just not as strong), stock reconditioned heads or RHS Pro Torker heads, or Edelbrock or... The combo needs to match your driving style & needs. Don't build a high reving monster when towing is what you're really looking for.
I guess the first thing you need to concider is your budget. The MOST important part in this build would be a good overdrive 5-speed. Tremec has truck 5-speed for about $1500.00 new. With this you can tow and get mileage without an automatic transmission failure.
Call me if you want to go over a parts list & your budget.

I have had my fill of automatic O/D transmissions. And I don't want a standard.(The wife will be driving it also). This time I am doing it right....
TH400! Since you don't normally tow in O/D, why would I need one? This truck will never be a daily driver and will only be used to tow my travel trailer and an occasional trip to Home depot. It might get 1000 miles a year put on it. So for me, the cheapest alternative is just to do a TH400 change over since it has a TH350. My transmission guy even tells me he can build the
TH350 almost as strong as the 400, but I don't want to find out he was wrong on a cross country trip to BFE someday.

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Originally Posted by jbright300

Hey techinspector1, what version of Dynosim are you using?

Jeff

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DynoSim Advanced Engine Simulation Version 4.20 with ProTools. There is a new version of this one out now, the 5.0 with ProTools.

This software comes with 800 cam files in it. There is a separate cam file you can buy for $49.95 that has 6000 cam files. If I had it to do over again, I'd get the 5.0 and the larger cam file. Total $150.

Bought an Edelbrock 7101 Performer RPM on ebay for $71.00!

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Originally Posted by jbright300

Bought an Edelbrock 7101 Performer RPM on ebay for $71.00!

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Score!!:3dSMILE: