just out of interest for future tuning what kinda power can a stock block on an 8 take, would a bigger turbo without upgrading the internals be out of the question?

 

Not out of the question...

I do know one thing, though... there are tons of threads on here of people asking how they should upgrade their Evo. I bet you one of those might be a similar path that you are thinking of. Or, at least, it will lead you in the right direction. Try searching and reading through some of those.