Borg Warner T10 vs Toploader

[Dan Case]

Originally Posted by Tom Kirkham

I believe I heard CS say that SAI used Pontiac gears in the race car transmissions. Can you shed any light...

Sorry no. I used to hear that decades ago myself, more specifically different gear sets were used for different venues along with different diameter rear tires and differential gear ratios. Most of the Cobra transmission information I have comes from Dick Roush. He can quote Ford, BW, and GM part numbers for all the sets without having to look them up usually.

The Feb. 6, 1964 reconfirmation of what was submitted to the FIA (with pictures of CSX2138 and the first Daytona Coupe included) shows L gear ratios standard and K ratios as an alternative. The M ratios are not listed at all on that document. SAI was into finishing late CSX22xx and early CSX23xx chassis at the time.

My black car (CSX2310, end of March 1964) came with a K set and I really like the ratios. Back when I use to run open track events at Hallet the car did extremely well on that short course. Extremely well means it was gears wise better for that track than any of the other Cobras running at the same time.

People working on Cobras with K sets can get real frustrated trying to make a Ford specification clutch disc slide onto the splines, they won’t. I know of a few main cases that got broken as people tried to force a transmission in place using the mounting bolts to attempt to make the transmission pull up into place. Won’t work, the ears on the transmission snap right off. I have heard of owners ditching K sets and installing M sets so they won’t have to worry about getting the correct clutch disc design again.