THM 350 or THM 400

I am looking for a Corvette 1968-1972 with auto transmission.
Does anybody know how to determine if there is a THM 350 or a THM 400 in a car?
Is there a list available maybe?

I found a car of 1972, the owner said : it is a THM400 but I am in doubt.

Who can help me????

My 75's Tranny says what it is on the bottom of the tranny pan. Turbo-Hydro Matic 400 I believe(been a while since I've seen my car). I am sure its stamped on the bottom of it though.

Good Luck
Scot

A '72 with a stock auto will be a 400.

One quick way would be to look at the shape of the pan. The 400's pan looks like a "pregnant" regtangle, while the 350's pan is a square with the corner cut off.

Good luck.

Thanks for your information Martin. I am ordering a nice Corvette convertible and want to ship it to Europe. I only want to be 100 % sure that there is a THM 400. With you information I am convinced now. Thanks again.

Kees

a friend told me that a 350 was a 3 speed and the 400 was a 4 speed auto. I brought it because I hadn't crawled that far under my '79 to see.
maybe that will help...

Both the THM350 and the THM400 were 3 speed automatics. The THM400 is a "beefier" transmission designed to handle higher torque loads and higher horsepower.

The 4-speed automatics were the 700R4 series.

Automatics-

THM400 - '68-'77. RPO "M40". 2.48, 1.48, 1.00

THM350 - '76-'79. RPO "M38". 2.52, 1.52, 1.00

THM350C - '80-'81. RPO "MX1". Lock-up version of THM350.

700R4 - '82only. RPO "MD8". 3.06, 1.63, 1.00, .76

NO VETTE IN THAT YEAR SHOULD HAVE A TURBO 350. ALL HAD THE TURBO 400. 350 PAN IS SQUARE WITH ONE CORNER CUT AT A 45 DEGREE ANGLE. 400 PAN HAS A DISTINCTLY DIFFERENT FUNKY SHAPE.

Don't forget the 200R4 4 speed automatic. Never put in a stock Corvette. Lighter duty than the others.

Also TH400 has the vacuum modulator valve on the RH side of the transmission, TH350 has the modulator at the back.

Without looking underneath, the TH350 has a cable kickdown connected to the carb, the TH400 is electric, with a switch over the throttle pedal. Joe