The shim in the rear servo would only make engaging reverse a little harsh (Same feel with the Cheetah tranzbrake). The low/rev band is not used in "1" if you are using the Cheetah RMVB 17156. The accumulator mods should not make any difference using the RMVB. The VBs are basically the same except for the transbrake. I have blocked the accumulator piston down with a rod to firm the 1-2 shift with the Cheetah RMVB.

John