I was reading about Nigel Rollason's A65 outfit. He said they were getting over 90hp. Running a 3 bearing crank and a 3 bearing G/box main shaft. They put a bearing where the alternator would go which also controlled end float, As with my set up except mine is outside the alternator. I'm rebuilding one at the moment, a 90degree 744 that the bottom end has not been apart since about 1998 when it was built. It was running fine with good oil pressure but the alloy rods though looking in good condition are getting old and without a remote filter we were wondering about sludge in the crank.
Before I had a plain spacer between bearing and threads on the crank and the threads under it were a bit worn. So I made this spacer to use a Norton spigot nut under the bearing. So it slides into the bearing so the hex section acts as a washer between it and the alternator rotor. Because a loose washer in there is very hard to assemble. Then the spigot nut threads under it.
Nigel said with these extra bearings primary chains gave no problem at all. As they would stay aligned. As late as 1986 the Hogg brothers on an A65 were taking wins in modern racing, causing headaches for Yamaha TZ700-750 outfits and 900 Z1s.
The outfits really tested drive lines and they showed just how potent A65s could be.