How do I tell if my crank is forged or cast? The parting line is thin in some places and other places it is thick. The crank is in a '96 Vortec 454. I bought a flex plate, but it is SFI approved and I think it is only for a steel crank.

The flexplate doesn't care what kind of crank it is attached to. I bet it is a cast crank, but the easy way to tell if you have it out is to hold it up in the air, and tap it with a metal object. If it rings, it is forged, and if it thuds, it is cast.

It's in the engine already. I think it is cast, but just don't want to shake the engine apart. I am adding a ZZ502 cam and cleaning up the heads a bit.

You really need to find out since these late model BBC's use different balancers and flexplates/flywheels on cast and forged cranks. Pull the pan and find some casting/forging numbers, then head to MorTec and you'll find your answer. I think there are only 2 cranks for Gen 5 and 6 engines, one cast and one forged. As I recall, there is a hatchet shaped counterweight in the middle of the cast crank that's not there on the forged unit, so that might help you identify it. Good luck with your project.

it has the funny looking counterweight. I guess I'll be returning that flexplate and searching for a different one. I had a hard time finding one that has a dual pattern so my converter will bolt up.