I have a 1960 Austin Healey with a Toyota 5 speed, likely a truck transmission. I say this because I was turning 3000 rpm at 60 mph in 5th gear with the standard Healey 3.9 diff. The desirable Supra boxes reportedly give much higher speeds at that rpm. I have now replaced the ring and pinion...
First I apologize somewhat for venturing into the Toyota Truck web site, as I'm kind of an outlier in the Toyota world. I recently purchased an Austin Healey 3000 that has a Toyota transmission installed to replace the very heavy and fussy original unit. This is regarded as a significant upgrade...