Borg Warner T10 vs Toploader

[Dan Case]

Case Material
Between SAI and Mr. Roush’s research the mystery time frame is roughly between when “iron” CSX2115 was completed (June 1963) and “aluminum” CSX2136-2138 (about August 1963). From your first post today I don’t think CSX2126 would be in the discussion because it was finished at AC Cars before CSX2080. Circa early February 1963 CSX2126 was a running car.

Gears
I just called Dick Roush. Dick has helped find parts and coordinate shop work of many Cobra owners repairing or rebuilding their original transmissions. As far as he recalled:

B sets = only in the iron cased Galaxie transmissions that happened to get redirected to new Cobras

J sets = he does not recall finding a J set in a genuine Cobra transmission, he allowed that it could have been possible but doesn’t recall any.

L (high nickel) sets = aluminum cased Cobra transmissions

K (high nickel) sets = aluminum cased Cobra transmissions introduced sometime in the CSX22xx range, example he knows CSX2246 had a K set originally, my black car CSX2310 was fitted with a K set.

M (high nickel) sets = aluminum cased Cobra transmissions introduced sometime in the CSX23xx range, his belief was that the later the chassis was the more likely it was fitted with a M set.

The tough part to deal with is chassis were not finished in order so it is meanless to think that since car CSX2xxx was fitted with "such and such" that chassis CSX2xxx±1 or 2 or whatever got the same part or assembly. Case in point AC Cars wise CSX2126 was finished at AC before CSX2080 was completed at AC. CSX2126 was rushed to SAI ahead of other chassis so even at SAI it was running much earlier than any other cars numercialy close to it.

[Tom Kirkham]

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

[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.

[Tom Kirkham]

That would explain why I never was able to find a Pontiac T10.

So where did the GM input gear sets come from?

[Dan Case]

Originally Posted by Tom Kirkham

That would explain why I never was able to find a Pontiac T10.

So where did the GM input gear sets come from?

Dick's only comment, "The K close ratio gear set is a nickel alloy gear set originally used in some 1957- 63 GM high performance cars."

Maybe that meant Corvette T10 ?

[Ghiblicup]

You are my hero!

I think today we can just try to be as accurate as possible and have "Likely atches of VIN sequences".
In any case that means if you have a "M" on a 1962 car, it very likely means it is correct type, but not the exact one.

Last question: The cast iron were Grey or "Ford blue"?

Originally Posted by Dan Case

Case Material
...

B sets = only in the iron cased Galaxie transmissions that happened to get redirected to new Cobras

J sets = he does not recall finding a J set in a genuine Cobra transmission, he allowed that it could have been possible but doesn’t recall any.

L (high nickel) sets = aluminum cased Cobra transmissions

K (high nickel) sets = aluminum cased Cobra transmissions introduced sometime in the CSX22xx range, example he knows CSX2246 had a K set originally, my black car CSX2310 was fitted with a K set.

M (high nickel) sets = aluminum cased Cobra transmissions introduced sometime in the CSX23xx range, his belief was that the later the chassis was the more likely it was fitted with a M set.

The tough part to deal with is chassis were not finished in order so it is meanless to think that since car CSX2xxx was fitted with "such and such" that chassis CSX2xxx±1 or 2 or whatever got the same part or assembly. Case in point AC Cars wise CSX2126 was finished at AC before CSX2080 was completed at AC. CSX2126 was rushed to SAI ahead of other chassis so even at SAI it was running much earlier than any other cars numercialy close to it.

[Mark IV]

Ford transmissions are always natural when new, they did not paint them. And "Ford Blue" was not introduced until 1966 model year production.

[Dan Case]

Originally Posted by Mark IV

Ford transmissions are always natural when new, they did not paint them. And "Ford Blue" was not introduced until 1966 model year production.

+1 on being bare but depending one year and model all kinds of paint color marks plus an engineering number stenciled on. In one of Colin's books (think it is one of his) is a picture of a very early HP289 dressed to go into a new Cobra at SAI with transmission attached and on the side of the iron cased Galaxie transmission is stenciled a large number.