yes it is sleeved. you can see the plug weld in this photo on the right upper rail inside. Yes I am going to run Super Comp. What thought is why not? Bring a Front Engine to the big National Show, so what if I go out first round. Maybe get some people thinking and scratching their head. especially the door guys with a bunch of coin in their motors to go slower. Oh and mostly have fun. I also like the thumbs up from the older generation.