The information I have is that Rare Bear has always had a 3350 since it was modified for racing. I have photos of it back to '74 wiith the cowling off. There is a Sea Fury named Dreadnaught with a 4360 that looks somewhat similar to Rare Bear from the side view, expecially with it's extra tall fin.
Racing and straight line speed runs are different animals. In John Penny's words (Air Classics July '96) "the plane experiences a significant directional trim change when rolling from straightaway into the turn around the pylons. Lyle and I estimate 55-70 lbs of bottom (left) rudder pressure is required to keep the ball centered in a five to six G pylon turn." He goes on to say "On the course at race power and speeds, the Bear is just plain hostile." The team has been challenged in recent years just to keep everything running under the terrrific stresses they place on the hardware.

In any case, matching the worlds most powerful radial engine with a 60 year old airframe and running both way beyond their design limits finally paid off with a win in Reno in 2004.