Ok, that is good info so far. I thought about just swapping the top end, but I looked up the pistons for the two engines and they are different. I was assuming this was for lower compression on the supercharged version, but that was an assumption. Anyone able to verify either way on that?

Is the HD diff worth the trouble? Seems like it would be easier to change the whole transmission if I go that route then to open up the differential.

Thanks guys, keep the info coming.