ok we took the flexplate out and it is externally balanced since the weights are on the flywheel. So now we are stumped why the flexplate keeps on hitting starter. THe engine is a 90 block so it is externally balanced also. I think the next step is to get a big bellhousing.

 

Could the bell housing be the problem?

 

we could use more info like what motor/ trans. and remember the 90 block will be a 50z so be sure to use the correct damper. but sounds to me you got a 164 tooth flexplate but a 157 tooth bellhousing causing the flexplate to starter problem. a larger bell should solve your problem but please give me more info to be sure.

 

YOU NEED A c-4 flexplate for 50 oz motor and correct size one at that... if you have the smaller bellhousing you need a 157 tooth

 

well its a 90 block on a c4, the bell housing before did fine with a 164 tooth with a 302, same tranny and bellhousing. I took the old flexplate out and it has the weight on the outside, this is what makes it external right? Well i also have a 85 351 flexplate, but it has a smaller weight on it, I will stop by autozone today to see what the 90 flexplates look like. Do you know how much space should be from the flexplate and the housing? I measered the depth of it and it came to 6 1/4 inches. The flywheel fits in the bellhousing but is a tight fit.