arapoda:

For the hardened diffs you will need to shim the left output shaft to put the diff gear closer to the input shaft(little copper shims in the bag). Put in enough that the diff does not move, but not so many that it binds. I have six in mine. I have had mine in for 4 months with no problems. With the old Pot Metal ones I had to repplace them every other race weekend.

The 18 CVR is a great engine and will totally transform your vehicle. The 18SS is a ittle slow off the line, not enough torque as the OS.