Factory Pushrods

Can factory pushrods be used with guide plates?

I wasn't sure if the factory had hardened them.

If all is correct should the pushrod even contact the guide plate? Or is there that much play in the stock rockers...  I've never really thought about it, as there is no need for guide plates with the stock valve train...

Back in the mid 70s I used a solid lifter cam in a 343 with stock rockers. After a couple drag racing events I was checking the valve lash. I noticed that some of the rockers had a lot of side motion at the push rod. Pulled the rockers and pushrods and some of the guide slots in the 291 heads were worn away. I needed guide plates. I used the stamped steel Pontiac plates. I cut them into individual units. I took the guide plates and the stock AMC pushrods too work, they had a Rockwell hardness tester. The plates and the rods checked out at 55 on the C scale. I installed and only had one PR got damaged. Checked out the problem and found a burr on the plate, removed it and no more problems. I'll assume the stud style rocker push rods are hardened. After that problem I also went to Crane roller rockers. You cannot use the stock rockers on straight studs with a solid cam. When using guide plates check the slots and remove any burrs and sharp edges.

I had a similar problem to amc67Rogue. I am using a Group 19 camshaft and matching NOS valvetrain. I found that after a while I was having a similar issue with the pushrod wearing into the guide slot. I used a set of guideplates for a small block chevy, which are separate for each pushrod. It has been working fine for 10-12 thousand miles and I have checked it periodically for wear and the pushrods seem to be holding up fine. They were billed as being "hardened", so perhaps they are a significant improvement on the factory items.

Chris

PS: The Group 19 cam is hydraulic, but it is higher lift than the factory item.