Builder,
I did put the car on the Dyno and was not pleased. The motor put out only 348 HP to the rear wheels. I am still working through that problem though. The cam is good to 76 to 7800 and the HP and Torque curve both peaked at only 5750. What I find strange is that both started to drop at the exact same time, so the engine is starving somewhere. The torque numbers were around 312 which is not good at all, but one thing, if you have a loose torque converter, which I have a 4500, you will get a lot lower torque numbers. A manual tranny car will always put up better numbers, even guys with auto's that have lock-up verters lock them up to get the higher torque numbers on the dyno. Our car club is having another dyno day in November and I hope to have made some changes by then and see if things are better.
I still have to do alot of tuning to figure out why the motor quits making power so early. I know it's not the heads and intake since I changed both and the car only went .14 faster at 11.54. I have the feeling it's in the jetting but don't have the time to get out to the track to play with it since I'm in the process of building a house right now. The good thing is when the house is finished I'll be only 20 minutes from the track where now I'm a little over an hour away.

Now remember you can slow the pistons down using the 400 crank by running longer rods if that's your concern. They have some pretty long rods available. Even if you go with the 350 crank I would go with a 6 inch rod. I just didn't have the money at the time to go with the longer rods when I built my 377, shoot didn't have the money for a good after market crank either. My compression is only at 11.41. To make it to the 600 hp range on a naturally asperated you would have to go quit a bit higher, then you will always have to run race fuel. I still run pump gas in my motor without any pinging at 36 degrees of total timing.
Good luck on your quest, I do like the 377 and it has a sound all it's own. I always get complimented on how good the motor sounds coming out of duel 3 inch flowmatsers.