last tim i checked the only difference was the pistons .. possibly a PnP job, but i don think much else...

if you are building it up already why buy a new engine, the 30HP comes froma raised comp ratio that you will lose just by swapping the pistons


and i believe you can buy type-s pistons from online vendors such as h-motors: http://www.hmotorsonline.com/shop/sc...age&item=10026