My son and I are mocking up the valvetrain on his 350 and the guide plates that came with the heads don't work. The pushrod slots are too narrow for the push rods. Has anyone dealt with this.

 

Which heads are you using?

 

Sorry, meant which pushrods.

 

Just stock ones right now to check everything. 5/16"

 

I can't say I've run into that on ANY SBC head ever. I would have to assume the guideplates are simply manufactured incorrectly. 5/16" pushrods have been used on SBCs since day one. There was never one with smaller (say, 1/4") diameter sticks. On some high end motors they swap to larger 3/8" sticks (to handle high spring pressures), but that's got nothing to do with what you're experiencing.

I assume you're not using offset rockers or anything weird like that, correct?

 

These are the guideplates and studs that came with the heads. We're using Harland Sharp rollee rockers but we haven't even gotten to the point of putting the rockers on.

 

So the slot in the guide plates aren't wide enough for the pushrod? Maybe a pic or two would help.

I'd send them back…you must have a defective set. I just installed Harland Sharps on my heads two days ago, and everything was fine. But I'm using AFR heads and the studs/plates they sent….