I'm getting ready to put my 350 that I took out of my boat (18 hours on the rebuild) and drop it in my 91 Bird, and originally I thought it was a 1 peice but my brother pointed out to me that it was a 2 peice and looks like my flywheel wont swap over, is this ture? Different fly wheels for pre 87? And what about the balancer? I don't wanna try to fit anything that isn't gonna wanna go. And, here is my block casting numbers in case somebody know's how or where to look them up, 10066338, and there was the number 92 in 3/4inch numbers about 3 inches to the right of the other numbers, maybe I thought that was the year and that it was a 1 peice rear main. Thanks for any help