I looked at all my books,no number that matches that one you listed--I stopped at the local junkyard and looked in their hollander interchange book--only number close to yours is 3973452 --thats a manual tranny flywheel for all the other small blocks except the 400,with a 10-1/2 inch clutch-.I assume we are talking a manual flywheel--I have one from a 72 350,it has two small "bumps" on the motor side that could be easily mistaken for counterweights,if you look at the back of the flywheel the bumps will be at the 4 o clock and 8 o clock positions if you hold the wheel with the bumps toward the bottom of the wheel--I'd make absolutely sure its the right one before you install it,since the wrong one will make it shake itself to death!.
Does a 383 motor need the externally balanced 400 flywheel,or is it rebalanced internally??(not that familiar with that build up-- /forums/images/graemlins/dunno.gif)I bought a 3+3 crew cab truck for 300 bucks a long time ago that was sitting at a gas station for months,the owner refused to pay the mechanic for installing another motor because he claimed it was "junk" a because it vibrated real bad--turned out the guy put a 400 smallblock in it,and thought it was a 350,and used the flexplate from the 350--I saw the problem right away when I noticed the harmonic balancer was counterweighted,and the flex plate was not(no inspection cover!)--I played dumb while I bought it--got a good truck cheep! /forums/images/graemlins/grin.gif
