The 3.6 is a decent swap - the g-50 tranny is an expensive one...

Instant G has a great calculator for the 3.6 swap with a 915. Just remember that for the most part - the 3.2 and the 3.3 turbo are almost the same from the jugs down. (turbo has a bigger oil pump) The 3.3 uses CIS - which is usually the first thing that the high HP turbo guys ditch.

Juan Ruiz is using a 3.2 Carrera engine (and g-50) and he's pushing 700hp.