Whats that I hear, sounds like 400's boy they sound good, OOOOOOOHHHHHHH crap that sounded like the snapping of a alpha, Damn there went another good alpha.

What do you use for a flywheel? I wanted to do this many years ago, but could not find a 400 flywheel that would fit the alfa (then 1 drive) belhousing. The 400 being external balanced and is not the same as a 454? This was always my short fall, whats the trick?

Ok ! You need to take a 454 flywheel and remove 70 grams from the big counterweight.
A good machine shop can do this. The flywheel you would want to start off with would end with 457. You could have motor internally balanced too using a neutral balancer and flywheel. I feel that if it's going to rev high, you better get a good balance job from a really reputable shop. It's amazing how motors are ballpark balanced from the factory anyway. Start mixing parts and all bets are off. Expect to pay at least $300 for the balance job. It really pays off. BBB

They make a counter weight that goes on the crank before you put on the flywheel. Available at any automotive machane shop, it's the same one we use for a 383 stroker, thats a 350 block and flywheel with 400 crank and 5.7rods.

4500rpm is all i go for my inboard sportfish/partybarge. i used speed pro hyperutectic dish side load this!!!i needed big torque and better fuel milage than a big block .i have top mouted starters so i had to cut a step on the fly wheel via lathe to swap the ring gear to the face side . i am confident that my engines will last a good long time.It's not like 350's are much better (350's still have side load and can still blow head gaskets)