'71 RPO Question

[BBB454]

Sorry if these are dumb questions, but is there any way for me to tell whether my car came with RPO M21 (4-speed Manual Transmission, Close Ratio) or M22 (4-speed Manual Transmission, Close Ratio, HD)? I can't find the tank sticker and don't have the original papers.

Also, what does having the M22 mean performance wise??

Thanks!
Barb

 

[billagroom]

Try this thread
http://www.corvetteactioncenter.com/forums/showthread.php?threadid=2349