I've got a 904 I'm building with a cheetah forward pattern manual valve body(the one with engine braking in 1st, picked that tip up here) 2800 - 3200 stall & disc brake LSD with 3.27:1. The diff is a BW78. Not sure if you have them over there. I think it's an 8 1/2", but there known to take some serious punishment. I'm also looking at putting a set of caltracs on it. Might make a good compromise for street & the odd trip down the strip. Wind them up for the drags, back them off for the street.