So I understand these were used on 72-73 Rx2 and Rx3. Later use continued on the auto trans Rx3. I hear there are large diameter ones and small diameter ones?
I need one to line up with the ring gear on a standard manual trans flywheel on a single distributer 12A.

 

well i don't know much bout them other than they came on the early 2s and 3s. but in all the yrs i've been dealing in rotaries and of all i've read bout them here, ur the first to mention large/small dia. so i'd say they're all the same. but of course, i've been wrong before.

 

the TD top starter ring gear position is a different position on the flywheel to the SD motors

also r100 manual uses a top starter and there is detail differences between the r100 and rx2 version
- dont know much about the drive gear sizes

i have seen an auto rx4 with SD 13b fitted ,, yet still had the top starter
,, god knows where that bell housing came from