sbc build

Trying to complete an essentially stock SBC 350 truck engine. Plain old stamped rockers, original pushrods, Summit heads. Most of the rockers appear well centered at the valve stem but a few are clearly off-center, No, 8 intake visibly moves sideways. Some do not seem to retain adjustment...

I know y'all get these questions a lot, but I was unable to find my answer searching the posts. I am starting on a rebuild of a sbc. It will be a 9.5:1 383. I'll be using a 600 cfm carburetor and Performer Air Gap intake. I have a 700R4 with a 3.08 rear gear, and have not decided on whether...