Thread: Help Me Pick Some Heads For Christmas Present

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[QUOTE=Nuckingfuts;572955]Ok I got it this time. The details are registering but I just hadn't prioritized them in my head yet. So prioritizing our list,

Originally Posted by Nuckingfuts

1. Change rearend gearing

Unless someone has changed out the differential sometime during the truck's life, I'm pretty sure it came equipped with a 12-bolt GM. Count the bolts holding the rear cover on.....
https://www.ringpinion.com/b2c/DiffD...&DriveType=RWD
We touched briefly on the ratio that would work best. Having been part of many different discussions and witnessing many different builds concerning the proper ratio, I have concluded that a 3.73 ring & pinion will work best with an overdrive transmission. I say discussions and witnessing builds because I never have and never will use an overdrive transmission on a hot rod build and I'll never advise anyone else to do it either. I feel that the only reason to use an overdrive transmission is for fuel mileage and I am not interested in fuel mileage in my hot rod. Fuel mileage is for my daily driver that comes from the factory with an overdrive transmission that I will never touch.

I see fellows using an overdrive transmission with a hot rod cam. Makes no sense to me. Any hot rod cam that you might choose (like the 204 that I like for your truck, has a minimum cruise rpm of 2200-2600 rpm's. Now, I ask you, how are you going to make any fuel mileage if you have to run the motor at 2200-2600 minimum. If you gear the rig to run down the highway at 1600-1800 rpm's, you are out of the range of minimum cruise rpm's that the cam grinder specified for that cam and you are not generating any fuel mileage anyway. Can you see the lunacy in this? You either drive a hot rod or you drive a stock cam rig. You cannot have it both ways, not with a carbureted rig at least. (224 intake cam-3000 to 3400 cruise rpm), (236 intake cam-3800 to 4200 cruise rpm). I hope you can see this, that the wilder the cam, the stupider the idea of an overdrive transmission becomes. If you want to run an overdrive transmission, put a stock cam in the motor, enjoy the ride and leave that hot rod nonsense to someone else.

So, that leaves me (Henry Hotrod) with either a 2-speed Powerglide or a 3-speed TH350 or TH400, or a C4 or C6 if using Ford motivation. With any of these choices, I will still use a 3.73 gear on a street driver. It's good for cruising and it's good for acceleration. If I were to build for a street-strip vehicle, I would gear it up into the 4's. I guess my all time favorite sound would be the fellow from my neighborhood who drove a '57 Chevy with a Rock Crusher Muncie 4-speed running through 4.56 gears and the sound of a Quadrajet opening up. Sounded like 14,000 rpm's if you know what I mean.

I would begin by contacting the differential specialty companies, such as Currie Enterprises or Moser Engineering and talking with the tech guys about the ring and pinion, a limited slip pig of some kind and axles. Sometimes these guys will know of a complete unit that is for sale somewhere. (I like the Auburn Limited Slip units).
Tech Support | Moser Engineering
https://www.currieenterprises.com/contactus-2
https://www.richmondgear.com/contact...ts-components/

Originally Posted by Nuckingfuts

2. Get the compression up by way of an iron head (I had no intentions of swapping pistons unless you suggested otherwise, glad I don't have to)

Pull a valve cover and find the casting number of one of the heads (cast in between the springs or pushrod holes). That's the easiest way to look up your heads and find out the combustion chamber volume. Then I can teach you how to find the static compression ratio through common math. Production heads are generally 64 or 76 cc's, so there may not be a lot of room to arrive at the SCR that you want with a production head.

Originally Posted by Nuckingfuts

3. New hydraulic roller cam set with 204 intake duration (your article chart shows a 212 duration cam for a 9.5:1 SCR though??)

A 204 cam will work all the way through 9.5:1. If I were building your motor, I would not use any more cam than that.
The chart is showing "ideal" and there is a little wiggle room either way.

Originally Posted by Nuckingfuts

4. 10" torque converter

A 10", 2500 stall unit would be just right right in my opinion. Just like with gears, lean on the manufacturers. Call 'em up an yack with 'em. They won't bite.
Contact Us - Hughes Performance
https://www.coanracing.com/contact-us
ATI Tech Support
I've known Jim Hughes for nearly 30 years, so if you can, try to give him your business. He does a lot to support racing and is a good guy. When I teched at Firebird years ago, Jim would always have a hot meal ready at his pit for any of the race crew, not just once in a while, but at every event. I paid him back by teching his car(s) at his pit, saving him time and effort from loading up and going to tech up on the hill. And by the way, I never, ever found anything wrong with Jim's car(s). First class operation all the way.
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