long tube cross ram info

Very cool, in deed! Hope you used a RB motor for the mock-up. The higher deck height will push the carbs farther apart than a 361-400 will.

As far as cam selection goes, a little more information is needed. What is the compression ratio? Rear gear?

For the sake of discussion, a 3000 lb car, 9.0:1 compression, 3.23:1 rear gear could use a cam with 195-214º duration @ .050". Bump the compression to 9.5:1-10.5:1 and the gear to 3.55:1-3.73:1, 215-224º @ .050" cam. The hotter cam will give a slightly lopey idle and low manifold vacuum. If you're running power brakes and/or A/C, you'll need a vacuum accumulator.

Hope this is helpful.