Harmonic Balancer, Crank, and Flexpalte matching help!

[spirockp]

I'm currently running a 1990 Ford 302 truck motor (non-roller) in my 66 Mustang. I am also using a 28 Oz flexplate and an orginal Harmonic balancer.

My question is on balancing the motor. Do I just match the Flexplate and the Harmonic Balancer? Or does the crank also have to be considered?

I'm getting a little virbration and was thinking this may be the issue?

Thanks for the help!

Peter S.

 

[xoxbxfx]

crank needs to be considered...

 

[spirockp]

After searching here again, I have read that the crank dictates the size of the weights. If I'm running a 1990 302 I should have 50 Oz weights, but I'm running 28 Oz weights.

Am I understanding this correctly?

Peter S.

 

[xoxbxfx]

that is correct

 

[spirockp]

Great! Time to drop the trans again........

Thnaks for the help.

 

[D.Hearne]

With a 1990 5.0 you need a 50 oz/in flexplate and balancer. You cannot mix and match. It doesn't work that way. Measure the 1990 balancer from the back side of the crank hole to the front where the pulley sits, and ditto for the 3 bolt unit you're trying to use. If that measurement is the same, simply drill the crank pulley to match the 4 bolt balancer. The 50 oz flexplate you need is available new thru Summit racing. It's a B&M part, 50 oz, 147 tooth flex. Think it's about $50.