Quote Originally Posted by westair View Post
What was this SK class? looks like it was pretty big back in the 70's ...... a lot of different types of boats running in it.

pic from AZOutlaw
Basically like Shooter said, it was an unlimited modification N/A 400 inch class, Later they raised it to match the SS class which had very limited modifications at the time. Eventually SK became Pro Comp, then Pro Stock with 500 inch limit.