Steve, I think that ManTran in Tallahassee has everything. The guys and girls there are quite knowledgable. I have gotten prompt UPS shipment and delivery as well as picked up at their shop. I got some shims from them and as to the big snap ring, I would replace it if there seemed to be any wear. It could be worn more on the eyelet tangs than the back curve. That could allow some angular misalignment with the front bearing and that is a problem spot anyway. If you reuse it, you could reverse it to swap the wear area but if it is questionable, throw it away. KD 2012 snapring tool takes the pain in th A** out of the large snapring. Borrow one if you can as they are about 45 dollars
The small snap rings on the countershaft pin don't carry any thrust as long as everything is running correctly. But I would look close and replace if they don't fit well. If the front bearing failed, there can be a problem with the groove in the pin. Don't pass on anything that looks questionable.
James McPherson
1stgen4evr