Ted,
Might I suggest our World products Man O'War "Cruiser Power" 427 Windsor, #102030.
It features a hydraulic cam, forged internals, dual plane intake and 870 Hardcore carb. A customer recently bought one for his Superformance Cobra and is very happy. Unfortunatley, it made 476 HP on the dyno, 26 above it's rating.
These have a broad and flat torque band and are not highly stressed, excellent for crursing. Dyno tested and warrantied. We also make Man O'War engines to 625 HP and 460 cubic inches.
See our two sites for details.