72 Buick Trans Production

[Guest]

I have a 72 Buick GS 350 with an original drivetrain. It has the 350 Engine but has a Turbo 400 transmission. Most of the Buick sights I have visited either says the did not make the 400 transmission available with the 350 engine or that they only made 1. Is there anyway to find out the real number? It just doesn't sound like my luck to stumble across the only 72 GS 350 ever made with a Turbo 400 trans. I have basically restored the Exterior/Interior of the vehicle and wanted to install a 455 motor, but I don't want to "destroy" a numbers matching car if it is rare. Any help will be appreciated.

Thanks

[BUICK RACER]

You should be able to find the VIN on the tranny to see if it could be original, and are you absolutely sure it's a 400??

[Guest]

I am sure it is a 400. The numbers on the trans. matches the vin except for the first letters. It starts off with B O M. It has no hook-up on the carb for a KICK-DOWN cable, did it hook up there? The guy said it was the original trans and had it rebuilt at the same time as the engine. He said he was the second owner and that is was original when he got it. ??? Who knows?? He could be mistaken.

[Guest]

Any More Sugestions?

[NTX5467]

One of our chapter members, a retired Buick service rep, ordered a '72 Skylark coupe (not hardtop) for his company car and then bought it for his mother after it went "out of service" in 1972. It is a normal 350 V-8 car, but with a THM400 in place of the THM350. He was surprised when he took initial delivery of it, but later found out that it got a THM400 instead of the more common THM350 due to a shortage of THM350s when the car was built. He tried to find out how many were built that way, but was not successful, as it seems to have been unique to only one shift that day. He also has the car now that his mother has passed on.

Although the THM400 is a heavier duty transmission, the downside is that it takes about 15 more horsepower to run than a THM350, if that matters. I wouldn't go to the trouble to change it for any reason, though!

Of course, the THM400 will have an electric kickdown switch that the THM350 does not. Oil pan shapes and case shape are unique to each trans too, as where the vacuum modulator is placed also is. Not much mistaking one for the other.

If the numbers you've found do "match" and other items and documentation do also match, be glad of it and enjoy the car. A THM350 is pretty bulletproof anyway, but a THM400 is more so.

Enjoy!

NTX5467