There are 2 bolt patterns on the back of a 6VE1, one is for the manual trans and is Isuzu specific, the other is for the 4L30E auto, and it is a GM 60 degree pattern. You could use a 700R4 out of an S10 or other 60 degree style transmissions. Adapting a 6spd to it would be interesting, you would need a custom adapter made as well as clutch/flywheel most likely.