Aluminum cylinder heads

@rumblefish360, I have a question about roller tip rocker arms ( I'm not using them ). I've read that they are known for the roller tips coming apart, what causes this? Manici does have the ductile iron rockers, which shafts do I need for these? I probably wouldn't be doing a cam swap till the winter. I figured that since I'm going to convert to a 4 barrel that would be a good time to swap out the rocker arms too.

Have not heard this about roller rockers myself. Even the less expensive rollers seem to do fine on moderate lift cams without issue.

You will need to measure for ball and cup style pushrods.