i would go tc all the way scion gave us ours to r&d parts and develop them for sales at the dealers(wont void warrenty)and also another bonus is they are incouraging the buyers to mod them.also these motors have already made over 500whp with STOCK internals with e-manage and a basic bolt on turbo kit!and can make high 3 to low 400whp and live for a long time.we are working with full race on our mani and we will be boostin very very soon so bring on the srt-4s and ls1's all you want!!!!!!!!!!!check us out at creativecompacts.com thanks