gt 390 build up cam and valve train hellllllp !!!

[mr greg]

I am building a 68 390 with Gt heads I purchased the Edelbrock rpm package the cam is a #7106 with 572-572 lift and 236-236 duration at .50 lift with matched valve springs. will this cam work with what I have or is it too big for my other stock valve train components . I have called the tech line for edelbrock before I made the purchase and they said it was fine so I purchased it. when I read the instructions it said I needed neverything under the valve cover adustable . so I called back several times and get mixed tech. advice. I did not plan on 500.00 more in valve train .I wondered If any real 390 ford guys know what I can get away with instead of techs that probably own chevys.

[rusty70f100]

Well, technically they are both right and wrong. Let me explain.

The way it came from ford, the valvetrain is non-adjustable. The way the "adjusted" for variances in the valvetrain from the factory was with slightly longer or shorter pushrods.

Now what if you want to use an aftermarket cam? You need to get variable length checking pushrods (Jegs sells 'em) that you dont run in your engine, you use 'em to see what length pushrods you need. Then you use what you have and buy pushrods as needed. That's how it "works" with the stock system. Really though, since the base circle of the aftermarket cam is most likely smaller than the stock cam, you'll probably need all new longer pushrods.

The best way to build it is to get adjustable rocker arms and ball / cup style pushrods. This allows you to accurately set lifter preload and you dont have to screw around with different length pushrods. DSC Motorsports has the rockers and pushrods. Napa should also.

It shouldn't be anywhere near $500 if that's any consolation.

[Six Niner]

mr greg i just got done getting my 390 overhauled. i think i paid around 120.00-130.00 per adjustable shaft at napa. and i think 40.00 for the pushrods at dsc. hope this helps.

[Putt]

One thing you will want to upgrade for that much lift is the rocker shafts. The stockers won't hold up to the spring pressures needed by that cam. Been there, done that!