It's not a 331 but I just finished and dyno'd my 507" Cadillac, going into a f/glass with steel fenders '32 Victoria. This was built for reliability and streetability so it's an 8.7 compression, we dyno'd it on 89 oct. and it was a true torque monster. Made 535 torque @ 4300 and 466 hp @5000. If you go to Cadillac Forum there are a bunch of Cad guys that hot rod the hell out of them. Most are the 472/500 engines but they also have an early engine section....lots of good reading.