I have a 1981 1/2 ton 4x4 with a possible 305 and an automatic. My problem is that the starter that the previous owner put on does not seem to mesh with the ring gear. I believe that the owner swapped in a new motor. I have tried using shims as it had none when I got it, but it just made it worse. I am not familiar with chevy's is there different starters for different motors? If so how do I tell? Please help this is very confusing.

Anyone?

First, take it off and using jumper cables see if it works. Then look at the teeth on the flexplate/flywheel to see if they're damaged. It could be the wrong one for the flywheel?

I can not figure out how to measure the distance between the flywheel and the starter gear. Any other ideas out there?

There's two different flywheels - A 153 and a 168 tooth. It's possible that the flywheel/flexplate is mismatched to the starter. Without knowing how your combo was put together it's hard to tell.

I had a friend who sold an early 80's Monte Carlo with a 305 that he had "pieced together" with a (IIRC) earlier year TH350 tranny that would start/run fine. However, it destroyed the starter 2 days after he sold it because of the mismatched flexplate, so I know it is *possible* a mismatched starter and flexplate can seem to "work" with a stack of shims, at least temporarily. He almost got sued over the whole deal and wound up buying the car back and putting the correct year 305 flexplate in it - problem solved.

Figure out exactly what you have (Engine year/displacement, transmission model/year, Flexplate application, starter application) and work from there.

I can not figure out how to measure the distance between the flywheel and the starter gear. Any other ideas out there?

-use a drill bit as a gage between the teeth