I have an S256 on my car, but I spun a rod bearing before I had a chance to really push it at all. Now I'm getting an engine built for it
(or as Jst4Cyl would say, I'm letting another guy boink my wife hoping she'll get pregnant so I can brag about it 
- although I see it more like sending my wife to a plastic surgeon to get bigger boobs and I get to brag about boinking her; afterall, the fun is in driving the car which the engine builder doesn't get to do) and hopefully I'll get some results before the summer is over. I also am using the bolt on housing like AWDER. I'm probably only looking to make 450whp max, so that isn't a real problem for me. When I'm ready for more power, if the bolt on housing won't accomodate that, I'll upgrade to the bigger T3.