I need help with a flywheel

[Jimmy_07]

I have a 1970 mustang fastback and I just dropped a brand new 351W. It is a hopped up motor and I was looking to put an aluminum flywheel on it. I also just had the c4 rebuilt. I have went through 4 flywheels trying to get it right but none are working, I know there are two different flywheel for the c4's and I narrowed it down to the smaller one, I just cant get the weights right on it, because the motor has a vibration in it caused by the flywheel. Right now I have 6 people trying to help me including three tranny shops but I've had no luck, maybe you guys can help. Thanks.

 

[66P51GT]

Since you are using a C4, you don't need a flywheel, you need a flexplate. Aluminum, as far as I know, is not even an option.

The flexplate has to match the crankshaft counterbalance. For '70 it should be 28.2 oz. 157 tooth. If your crankshaft is internally balanced, you need a zero balance flexplate.

Here is a link to a 157 tooth 28.2oz. flexplate from Summit:
http://store.summitracing.com/partdetail.asp?part=BMM-50236

Here is a link to a 157 tooth zero balance flexplate from Summit:
http://store.summitracing.com/partdetail.asp?part=BMM-50246

Hope this helps.

Edit: Spelling, clarified link descriptions, added zero balance link

 

[1320stang]

My Motorsports catalog shows a 157 tooth 28.2 oz. auto flywheel for a small bellhousing C4 behind a 289/302/351W,C,M part. no. M-6375-F302 and a 164 tooth 28 oz. auto flywheel for a large bellhousing C4 behind a 289/302/351W,C,M part. no. M-6375-G302