[d2_willys]

Curious what automatic transmission was offered in a 64 GTO with 389 engine. Would it come with ST300 2 speed? I know that 64 Pontiacs used both Roto 10 and dual coupling hydros in the big cars, and the Tempestorque (ST300) in normal tempests, but what about the GTO? (The ST400 was only available in Buick and Cadillac in 64).

[ponyakr]

I think the 2-speed is the only auto that was available in the 1st 3 GTO's. The TH400 came in the '67.

http://books.google.com/books?id=MGz...%20%3F&f=false

[stevep]

Yes, an Automatic 1964 GTO would only have an ST-300. 400's didn't show up in GTO's until 1967.

[d2_willys]

Originally Posted by stevep

Yes, an Automatic 1964 GTO would only have an ST-300. 400's didn't show up in GTO's until 1967.

This seems kinda dumb, as Pontiac came up with the BOPC pattern in the first place. 61-63 389/421 engines had the BOPC pattern, but no block mounted starter. Some 1964 blocks had block mounted starter bolt holes. With this in mind, it would seem that in 1965 Pontiac would go with the TH400.

Buick and Cadillac used the TH400 with their own bell patterns till 1967, but Oldsmobile went with the BOPC pattern in 1964 generation 2 rocket engines. 1965 Oldsmobile used both 300 and 400 turbos.

So why was the Pontiac people stuck with a 2-speed automatic? And it didn't even have switch pitch converter, as Buick and Olds did.

[twooldgoats]

Originally Posted by d2_willys

....
So why was the Pontiac people stuck with a 2-speed automatic? And it didn't even have switch pitch converter, as Buick and Olds did.

I wouldn't say "stuck with". The two-speed automatic in those years was a great transmission for those who didn't have (or didn't want) a 4-speed. I ran both a '65 convertible goat clone and a '66 GTO HT with the two-speed and really liked it. Very smooth and plenty fast.

Jim

[stevep]

That ST-300 was OK, but not a great transmission by any means. Ford and Mopar stopped using 2 speeds far earlier than GM did.

[twooldgoats]

Originally Posted by stevep

That ST-300 was OK, but not a great transmission by any means. ....

For the first three years, all automatic GTO's came with that transmission. As far as I know, they never had a reputation for being weak and they certainly didn't hurt GM's performance image. Not everyone had a four-speed back in the day, you know.

I think the GTO had enough power in a light body and they didn't need a three-speed automatic, anymore than my Tempest race car does.

Jim