My complements on the site, I stumbled onto it tonight and joined. Aside from the guy who has found a way to defy physics and spin a big block to 10K RPM, your members are well informed and the replies are great and sincere.
My problem, I recently purchased a 1967 Chevelle with a freshly rebuilt 454 Big Block in it. The seller had no information on how it was built although it looks to be pretty much stock. The engine recently developed a rod knock (to many 10k passes) in my quest to repair this (new crank and bearings, the old crank was cut .020” and poorly fit and finished, this is probably what whipped out the bearings. I had 40+ PSI of oil pressure)
I found several of the rockers seem to be out of alignment, they are not sitting square on top of the valve stem. Guide plates are in place the heads appear to be stock cast iron square port heads, the block is newer (7.4L cast in the block)1st generation with 2 bolt mains. Is there a cure for this, the push rods are not bent and all else seems normal.
My concern is it looks like the tips of the valve stems are taking the brunt of this and I don’t want any more problems. Hopefully I have explained this adequately, if not ask away and I will try to provide answers.
By the way I truly believe if you run your big block in space where weight is of little concern you can spin the heck out of that little bugger, the lack of oxygen will limit you quit a bit though.

You must loosen the studs and move the guide plates around until they are correct. Sometimes this requires cutting the guide plates because nomatter what you do you can't get both rockers lined up. Not real hard to do it just takes time.