TH350 Level 1
Horse Power: 400
(Up to 400 ft-lbs Torque)
Converter: 12” High Performance Furnace Brazed
Master Overhaul Kit with High Energy Frictions and All New Steel Plates
High Flow Filter
Transgo Shift Kit
Updated High Performance Boost Valve
New Front Band
New Torrington Bearings
Thrust Washer Kit
New Low-Reverse Spring & Roller
Hardened Intermediate Race
Custom Machined 5-Clutch Direct Drum Piston
5-Clutch High Capacity Direct Drum
High Volume Pump Assembly with New Gears
New Chrome Transmission Pan with Drain Plug
New Speedometer Drive Gear
New Speedometer Driven Gear
20,000 GVW Hayden Transmission Cooler
*All transmissions include Installation Kit: Universal Fill Tube and Stick, Universal Transmission Mount, Universal Converter Cover, & ATF
The Turbo Hydra-matic 350 was first used in 1969 model cars. It was developed jointly by Buick and Chevrolet to replace the two-speed Super Turbine 300 and aluminium-case Powerglide transmissions. So, although it carries the Turbo Hydra-matic name, the Hydra-matic Division of General Motors had little, if anything, to do with its design. The 350 and its 250, 250c, 350c and 375b derivatives have been manufactured by Buick in its Flint, Michigan, plant and by Chevrolet in Toledo and Parma, Ohio, and Windsor, Ontario.
Some would suggest that the THM350 (or Turbo 350 as called by drag racers and car enthusiasts) was based on the earlier Buick Super Turbine 300 — some components interchange between the two. Both Chevrolet and Buick divisions produced the THM350.
The THM350 was also regarded as a 'three speed Powerglide' and during its development, was generally called this. Although it uses the same torque converter as the THM400 (sans variable pitch stator) it has a familial resemblance to the 1962-'73 Aluminum Powerglide from Chevrolet and was largely derived from the Chevrolet design. One important difference in the THM350 compared to the THM400 is there is no fixed center support midway through the geartrain, this important difference in layout permitted THM350 to be adapted to the Corvair where the drive and driven ends are the same. This feature was not exploited but Corvair may have eventually used the THM350 had it remained in production, and Chevrolet was experimenting with mid-engine Corvette designs that might also have used this advantage had they ultimately reached production. Air cooled versions (with a baffle on the torque converter and air intakes cast into the bellhousing) of the THM350 appeared mid 1972 in Chevrolet Vega and Nova 6.