WS7 is a great motor, if you don't want to drop the cash, pick up an S7, its around 50 cheaper and there is no difference in power, just in the crankshaft coating. Also, you will want to replace yor spur gear that came on the Sports and go with a kit spur, also check the shimming of your diffs cause the RB motors make a LOT or power compared to a sport engine, if it is all not together nicely, it will strip them out.