I have a Billet Steel flywheel right now, dont ask why i didnt get aluminum, i got it on a complete long block which I got my heads and other parts from. On the back of it is what it looks like to be a weight held in by an allen screw. Would this be bad to have on my motor, is it a different oz. or different type of balancing than my 306? The block it came off of was a 308? (.040 over) block with good condition internals. It's not a stroker since the rods say Ford on them. I think the flywheel was heavier than a stock (idk) since it certainly wasnt lighter than stock. Could a heavier flywheel cause engine unbalance or any type of premature wear? I heard people use heavier flywheels b/c they store up momentum and helps you launch quicker.