Had one of the 31" inboards with a K&B .21 when I was a kid (always wanted all three though!), and was able to just recently acquire all three, the 31", 40", and 46", will be running an OS .21 in the 31, OS .46 in the 40, and K&B .91 in the 46, ahh trips to earlier years!!, BTW these hulls are still available from hyperformance products, you have to call though, as they dont list them online, and they prime in the mold now, the white hatch on the 40 is a new production from them. Don't know how competetive they'd be now as they are considered a deep vee, and I've been told they run best with the semi-subsurface drive that they originally were set up with, and that is how I plan to build them. No clubs in my area anymore so racing isn't my concern! The Prathers were some of the best in their day (tunnels and vee's)!
