Do diffrent heads require diffrent length pushrods?

[skiwesser]

I'm going with either Edelbrock perf. or AFR 165's, Both of which claim you can use all stock components, valvetrain too if pedestal versions are used.
Now, what about pushrods? If the spring installed height is not the same as stock than stock length p-rods won't work will they.
I would assume I'd need shorter p-rods, as stock springs bind at like .509 lift and both aluminum heads above will take .575"&.550",respectivley, so wouldn't they're spring installed heights be taller?
I've never changed heads but I know all this stuff is readily available as I'm the only one left running E7's!! Any advice or opinions on any of this rebuild plan is greatly appriecieted.

New rebuild under way, 306, Forged pistons, Eagle rods, stock crank, Typhoon intake ('cause I got one), 65mm T.B., 70mm "cobra" air meter ('cause I got 'em), AFR 165 heads or Edel. performer's, Trick flow #1 cam (221*/225*@.050 .530/.542 lift W/ my 1.7 RR's).

Wes

[Gearhead999]

You bet the pushrods are different. They are also different from head to head and engine to engine. Deck height is different and assembled height is different.

I recently purchased a set of Canfield heads. In the instructions that came with the heads they tell you all about specs and such. On the back of the instructions this statement is printed.....

"Good valve train geometry starts when the right length push rod is used for your specific combination of deck height, cam base circle, lifter length and choice of rocker arms. The fact is, if you are using stock length push rods, your valve train geometry is probably wrong. Before ordering push rods, BUY AN ADJUSTABLE PUSH ROD and determine the proper length for your combination."

That about sums it up.

[skiwesser]

Agian I have no experence with this stuff. Both my Bros. have put together several motors, but niether know about this.
Can we adjust the adj. p-rods ourselves?
Little Bro is a chevy man & he adjusts his lash (or whatever) with the car running, at least he did for a guy and fixed it in like 15 Mins.

[Gearhead999]

The adjustable pushrod is only one, it is used to determine what length pushrods you need to buy to install in the engine. You do this with only one adjustable push rod.

You should get a book on the procedure, so you do it properly. It means a lot in the engines power.

I'll check Wednesday and get you the name of the book about the correct way to do this.

[skiwesser]

Cool, Thank you.
Wes

[~The Jester~]

Proper valve train geometry is PARAMOUNT!!!! But fear not, it's not rocket science. Or is it? hehehehe Not difficult to do, just make sure you understand what the book is telling you before you dive into it. Take your time, do it correctly, and you'll be just fine!

[Gearhead999]

Get the book...."How to power tune Ford V8 small block engines". It's all about small blocks. SpeedPro Series. Veloce Publishing. Des Hammill, author.

I have seen this book in Borders Book stores. The procedure starts on page 78. Well explained and easy to understand.

Good Luck, and have FUN.

[skiwesser]

Where do I find an adj. p-rod? Summit only has them for BB chevy

[Gearhead999]

The book tells you how to make one.

[Ieatcamaros]

Here is a link from Holley's site that tells you how to verify valve train geometry. It is a pdf.

Here is one from comp cams website.

Here is the adjustable pushrod you need. Well, I see the link didn't do exactly right. It is the shortest one 6.125 - 7.500 range.

This should point you in the right direction. If in doubt, ask.

[Rev]

The instructions that came with my TFTW heads explained how to use the adjustable push rod to get the right length for proper valve train geometry. I did get my adjustable push rod from Summit. They did have them then (several years ago). You may have to call and ask them about availability and price.

Rev

[skiwesser]

Great, thanks guys!!