We didn't thinked about yet

I have heard that if you use a 940 turbo manifold, the turbo will go clear. And the 940 manifold is also better manifold than the 740.

That is correct on both counts...however...it's a good idea to enlarge the hole (to T3 gasket size) at the collector using a carbine burr or similar - the hole is tiny from the factory!

cheers

James