Re: AOD to c-4 conversion issues

Sounds like the convertor is not seated in the front pump, when you tighten the bell housing bolts will the convertor still wiggle in the flexplate. It should not be putting any pressure on the flex plate at all, you should be able to push the convertor at least 1/4" back from the flexplate. If it's bound up you may have damaged the front pump in the trans.

Another problem I see is you have a 91 engine, if I remember correctly they are 50oz balance, the 65 is 28oz balance so even if you do get it runing it's going to vibrate it's self to death.

You do need the block plate thickness behind the starter.