TVR T5 main shaft 5th gear snap ring...

Paul, it is your musings that bought up the 27 spline, that then led onto the GM post, I have fired off an email questioning to 5speed.com.
Here is the spec on TVR's listed snap ring 1000-139-032 (1.1250 ID, 1.3725 OD, 0845 thickness) I have ordered two, BUT these are listed IN Ford kits as the one to do the Ford. A@