i'm wondering what pushrods to get for the cam install. i'm going with comp hi tech chromemoly but should they be 5/16 or 7/16??? then i will also need guideplates.. correct?

 

The type of Roller Rockers determine the hardness of the push rods. I.e, if your Rollers are Non-Self Aligning, they will need quides to keep the push rods on the rollers on the valve stems. The need for hardened push rods is because the rods rubbing against quides will tear the rods up if they aren't hardened.

If you are going with SA (self-aligning roller rockers---the roller tips have little washer-type quides on each side which keep the roller in touch with the valve stems) you do not need quides and therefore you do not need hardened push rods because they have nothing to rub against.

On the other hand, having hardened, quality push rods is a good idea anyway.

So the cam doesn't dictate the push rod by itself, however the more aggressive a cam might be, even with stock rockers, the better off you will be with hardened push rod.

As far as dia/size, I'd go with whatever the cam manufacturer suggests.
As far as length either +or - stock, tis a good idea to measure the size needed which provides the best geometry (i.e, how the rockers contact the valve tips) stock length might be appropriate, but as long as you intend to go with the hardened ones, it would be wise to see which length will provide the best geometry. You can get an adjustable rod to do the checking.

 

Read this thread on pushrods.

http://web.camaross.com/forums/showt...light=pushrods

 

Thanks for that BLACKDOG, saved me from posting it!

Bret

 

get the trickflow' instead of the comp hi-techs, they are the same exact pushrods made by the same place to the same specs, but the only difference is they have trickflow engraved on them instead of comp, oh yeah and they are $60 cheaper.