RCU had a review on a GSP Corsair a while back. 75.5" WS, 12.4 lbs, and an RCV90. The reviewer was very impresses with the RCV, but as you know, reviews are always on the positive side.

I think RCV engines are perfectly suited for small and mid-size warbirds. I'm currently breaking in a RCV90 for my 1/8 TF Corsair.

As for 3-bladed props, the only one on RCV's list of recommended props is 15.75x13 3-blade... for both the 90 and 120 sizes. I read somewhere that the 120 will give you an few hundred extra RPM over the 90 with the same prop.

Juice