Balancing a 302
I need to balance a 302 cui engine correctly, therefore I need your help:
I have a 66 mustang with C4 tranny and a freshly bought used 302 engine. The cast-number of the block is D90E-6015-E3A and the block has no one-piece seal at the back.
The damper coming with the engine is 28oz (cast no is D6ZE-6316-A2A) while the mounted flexplate was a 164 teeth 50oz for a AOD (50oz is my guess, code on the weight is "EOSP", size of weight is kind of small but there is a large hole in the plate on the opposite side of the weight)
The flexplate given to me as fitting for the engine and my C4 with small bellhouse now looks like some 28oz imbalance (157 teeth, no hole, size of weight similar to a 289 28oz flywheel).
As I was told everything would fit I put all together, the engine runs nice, but only if I do not raise rpms above about 2000...
At 2000 or maybe 2500 rpm the car starts shaking roughly. I immediately stopped the engine and now I am trying to identify the used parts correctly for replacing the misfitting parts.
I never heard of a combination of 28.2oz damper and 50oz Flexplate running fine...
Can you help me out of this mess? At the weekend I check the cast-no of the crank...
Any help is appreciated, many thanks in advance!