So, the issue is the rockers hit the spark plug tubes for the second set of plugs....... Aren't those extra spark plug tubes going to be there no matter what heads you use?
I edited to say "IIRC", because it's been a few years since I talked to him. I thought it was rocker clearance. What I do remember is the advice from Indy to dent the spark plug tube, and how angry he was about it.
Mike Beachel
I didn't write the rules of math nor create the laws of physics, I am just bound by them.
