'63 Impala T-10 4-speed identical to Corvette?

[G B.]

I'm looking at a Borg Warner aluminum case four speed that is dated early 1963. The main case is cast "T10D-1" like a '63 Corvette case, but it has a large diameter (4.625") front bearing cover rather than the small 4.125" diameter Corvette bearing cover.

The stamped VIN derivative begins with a "B". I assume this means this transmission was originally installed in a non-Corvette vehicle (probably an Impala) assembled in the Baltimore GM Assembly Plant during March, 1963.

I always thought all '63 Chevrolet/Corvette Borg Warner 4-speeds used the same front bearing cover. Now I think maybe not. Did Borg Warner use the same T10D-1 main case with different diameter bearing covers for Corvettes and Chevrolet passenger cars in 1963?

[Joe L.]

Re: '63 Impala T-10 4-speed identical to Corvette?

Jerry------

For 1963 Borg Warner T-10's, the front bearing retainer bolt pattern was the same for all Corvettes and passenger cars EXCEPT those passnger cars equipped with 409 cid engines. Transmissions for that application used the larger retainer bolt pattern. In 1963, I believe that Baltimore was building full size passenger cars, so this would be consistent with a 409 application.

[Clem Z.]

maybe the 409s did *NM*

[Loren L.]

My suspicion would be that this is somehow

tied to the running change from T-10 to Muncie in 1963 - I have seen 421 bellhousings with BOTH sizes - if memory serves, the difference between
passenger car & Corvette T-10's in 1963 is the length of the shifter rods due to a different mounting for the shifter. FWIW

[G B.]

The answer?

Okay, it looks like the '63 passenger Borg Warner 4-speeds were all identical to the Corvette transmissions except for the front bearing cover on 409 cars.

I looked in my 1966 Chevrolet P&A Catalog and found only one main case listed, #3792694, for 1963 Warner 4-speeds. I assume this is the T10D-1 casting.

However, there were two front bearing covers listed. The first was part #604932 with an O.D. of 4-3/16". This bearing cover was used on Corvettes and small block passenger cars. The other cover was part #3741458 (with casting #3741458) that was used on 409 passenger cars. Since only one main case was used, the bolt pattern must have been the same for both bearing covers. This seems to be verified by the transmission I'm considering right now. It has a 4-5/8" O.D. bearing cover with the same bolt pattern as the smaller 4-3/16" Corvette bearing cover.

[William C.]

Re: '63 Impala T-10 4-speed identical to Corvette?

In '63 the 409 engine used the '62 style aluminum bellhousing, and thus the need for the alternate bearing retainer. The '09 did not use the block mount starter in '63.

[Verne Frantz]

Re: '63 Impala T-10 4-speed identical to Corvette?

Joe,
Jerry had it right in the first place. The bolt pattern is the same on both. The 409 retainer is larger, but has the smaller bolt circle. The 409 retainer is unique in that the bolt holes are not right at the edge as they are on the smaller retainer. The cases are identical.
Verne.