What pushrod length do i need

[hound51]

I have been rebuilding an amc 76 304 engine and have been hung up on getting the right pushrods for it. The stock length is 7.8 or 7.82 and from what i have seen i can not use that length with my roller rocker set up. I'm running harland sharp rollers, s4004-7 and the ratio is 1.6. Does anyone know what size pushrods i need to get or knows where to get the information? any help would be great.

[AMX69PHATTY]

Best way to be sure is to get a pair of SOLID Lifters, mine are Mopar,
and a pair of adjustable checker pushrods, I have ones from Crane.
The Solid Lifter Pocket is .252 Deeper than the Crane Hydraulics I have,
so this difference has to be figured in.
Use the solid lifters and adjustable pushrods to determine the proper length.
Proper length is when the Rocker tips rides over the center of the valve tip.
Lunati has how to information on thier webpage.
Use a marker on the valve tip and the Rocker will rub it off when the motor is turned over by hand once or twice.
Usually, Valve Closed, Rocker tip just to the outside of valve tip center,
and Valve Opened, Rocker Tip just to the inside of valve center.
Pushrod length can be fudged around a little bit to use available lengths.
I have what used to be called Crane Hi-Intensity Roller Rockers,
and use pushrods that are Stock Chevy length +.100 that were like $35 from PAW.
Hope your Intake Manifold isn't bolted down yet......

[Holeshot]

You do HAVE to use adjustable pushrods when mixing parts from different manufacturers, ESPECIALLY when using a roller cam. No way around it.

I do know that the most common pushrod LEN is the SBC +.100", & that is what my Comp roller valvetrain uses.

So many variables that it must always be confirmed by using the adjustable pushrods.

[AMX69PHATTY]

In the PAW Catalog they show Chev +.100 length as 7.894

In the Crane Catalog they show Chev +.100 length as 7.865

Whereas like you said stock '71 & up AMC length is 7.800 or 7.820.