OK Draco,
Lets give you some information to chew on. First of all I'm using Dyno 2000 from
www.motionsoftware.com. The numbers below are from my engine workup using the items I specified in the previous post.
351 cu in 518 hp@6,000 506lb/ft@4,500
393 cu in 519 hp@5,500 537lb/ft@4,500
408 cu in 520 hp@5,500 549lb/ft@4,000
427 cu in 518 hp@5,500 567lb/ft@4,000
Another deciding factor in going the 393 route was that Speedway motors had a stroker kit for about $1,100 which included h-beam forged rods. The other kits I found were much more expensive. If that 393 won't move a cobra I'll quit!
Good luck,
h dog