Replacing pushrods

[Mrturner1]

Might have seen my thread on squeaking tapping #8 cylinder. Re-used the old stock pushrods in the new top end rebuild, bad idea damage is small because I caught it in time though. I have a 355 with a comp 280H cam and guide plates in the heads. 1.52 PRW roller tip rockers (probably replacing all of them though with whatever is on the shelf at Orielly speed shop. Looking at Comp part #7812-16 which says STOCK LENGTH. The stock pushrod length is 7.794" correct? These say heat treated but does that mean hardened? I need hardened because I have guide plates. Also wondering what happens if the pushrods I replace mine with are a bit longer, like Comp part #7372-16 which ALSO say stock length, however they are 7.800" and 3x's the price.

Matt

[davepl]

I may have covered this in a PM, but it might have been someone else, forgive me if I'm repeating myself:

Normally you want the "right" length pushrod. There's no standard except for all-stock parts. Once you change the cam the base circle is different. Lifters could be different, rockers could be different, and so on.

Normally you want to verify that the tip of the rocker is riding in the CENTER of the valve stem, and that's what's important. Have you checked?

If it's at all off, like it's mostly over on one side of the valve stem, then you need an adjustable pushrod to check for length and order custom pushrods. Sucks, but so does bending and breaking stuff if it turns out you needed them.

You haven't gone full roller or anything exotic so you might be spot on fine with the stock lengths, but its worth checking to be sure.

[Mrturner1]

Originally Posted by davepl

I may have covered this in a PM, but it might have been someone else, forgive me if I'm repeating myself:

Normally you want the "right" length pushrod. There's no standard except for all-stock parts. Once you change the cam the base circle is different. Lifters could be different, rockers could be different, and so on.

Normally you want to verify that the tip of the rocker is riding in the CENTER of the valve stem, and that's what's important. Have you checked?

If it's at all off, like it's mostly over on one side of the valve stem, then you need an adjustable pushrod to check for length and order custom pushrods. Sucks, but so does bending and breaking stuff if it turns out you needed them.

You haven't gone full roller or anything exotic so you might be spot on fine with the stock lengths, but its worth checking to be sure.

Yep that was me I'm lucky to have an auto parts store that has a small speed shop in the back with hot rod parts. I did check to make sure that the rocker tip was riding on the valve correctly, so in theory the replacements should be exactly the same size as the ones coming out. Only problem is some are ground off at the rocker tip, others are not so that changes the length unless I find a good one. So far only one rocker arm is galled, but I'm going to replace them all to be safe, I'm sure there's incorrect wear on some if not all of them

[mike16]

arn't pushrods heatreated at one end? I think the heatreaded end goes toward the rocker arm and guide plate end

[hugger6933]

Hard push rods are the heated ones. Just different nomenclature. I don't get to use that word very often.

[Mrturner1]

Originally Posted by hugger6933

Hard push rods are the heated ones. Just different nomenclature. I don't get to use that word very often.

That is a pretty cool word.

It said use with guide plates and heat treated so I assumed they were ok. Good to have confirmation though