How do 318 powered A-Bodies do in NHRA PURE Stock?

Just wondering....helped a friend road race in a "stock" class years ago. Memory is very foggy but rules required runners to be stock cc. Seem to remember that guys would port the snot out of them, and then mill the intake face down to get the volume to the right cc and then install "spacers" between the intake & heads. Got away with it because the rules said the head had to be xx cc's...but the rules did not specify that you could not run a spacer. Like I said it was damn close to 30 years ago so my memory if probably a bit off. I do remember helping a friend who road raced bikes and they had a stock rule. And it was well known that the rules were open for interpretation..........there was one guy that ran a 600 that flat out would smoke the same brand bike going down the straight-a-ways......I am talking 6-8 bike lengths...