A J-pipe will seal ok, you just need to make sure that you put 1 or 2 braces where the turbo mounts so its not relying on the 2 flange nuts to hold it up, the braces support the turbo instead.

I ran a H145 in my turbo car with 100kw atw with no worries. If your mature enough to "NOT DO BURNOUTS!!" it will be ok

Like Dodgeman says... J-pipe, SU carbie, small turbo... job done...

Maybe I should make some kits and sell them?? Its not that hard...

Also with people who have blown head gaskets on low boost... did you lock the dissy so there is no mechanical advance, so when revs and boost increase it reduces detonation and stops from blowing head gaskets?????