Dave, I am curious now. If your Pace car is a 4-speed, then it should have the larger 168 flywheel (11" clutch), which the 8338 starter fits. If you were able to install and use the 8361 starter, your car must have the smaller 153 flywheel (10.5" clutch). Hmm, if it mounts and runs, did the nose get swapped? I just looked at the 1970 HBC 8338 starter ($450) and it has a nose with the long/short bolts (strange).
Anyways, I have a 9B4 8338 starter I bought from Jerry. But its a bit early for my May/June SS350. If you run across a April/May starter, maybe we can do some horse trading.
As to the bolts, the repro ones I found years ago look similar to the GM ones, but are a bit long. I had to use a washer to mount it, but that's fine. My car is not on the road yet
. I just have to keep my eyes open for a more reasonable GM one at the swap meets.