Shop TH400 Torque Converters and get Free Shipping on orders over $99 at Speedway Motors, the Racing and Rodding Specialists. TH400 Torque Converters in-stock with same-day shipping. TH400 Performance Automatic Transmissions and Parts from PATC. PATC GM Performance Transmissions and Parts, TH400 and others. PATC builds TH400 performance transmissions in many levels. PATC is on the cutting edge of performance rear wheel drive American transmission development. Straight-Cut Pro Glide ® ATI’s most popular Bracket & Super Gas Powerglide racing transmission. The Pro Glide comes equipped with a 9310 Straight Cut Gear Set (with warranty), Precision Balanced Carrier with Heavy Duty 4340 Output Shaft, 7 Clutch Drum, High Flow front Pump & heat treated pinned stator tube, plus an 'Instant-Releasing' External Solenoid Brake that moves the release valve. Th400 17 tooth speedometer drive gear: gm # 8629548: $25.00. To order and ship today call 800-999-9555. GEAR VENDORS, INC. 1717 North Magnolia Avenue, El Cajon, CA 92020 Toll Free 800-999-9555. Telephone (619) 562-0060. Fax (619) 562-1186.
| GM TH400 SPEEDOMETER PARTS | |||
Th400 speedometer Hold down fork | stainless steel | $6.00 | |
Th400 speedometer housing 34-39 tooth | billet aluminum | gm # 1362294 | $55.00 |
Th400 speedometer housing 40-45 tooth | billet aluminum | gm # 1362293 | $55.00 |
Th400 speedometer gear 34 tooth | gm # 9774413 | $10.00 | light green |
Th400 speedometer gear 35 tooth | gm # 9780387 | $10.00 | pink |
Th400 speedometer gear 36 tooth | gm # 1359270 | $10.00 | white |
Th400 speedometer gear 37 tooth | gm # 1359271 | $10.00 | red |
Th400 speedometer gear 38 tooth | gm # 1359272 | $10.00 | blue |
Th400 speedometer gear 39 tooth | gm # 1359273 | $10.00 | brown |
Th400 speedometer gear 40 tooth | gm # 1362048 | $10.00 | black |
Th400 speedometer gear 41 tooth | gm # 1362195 | $10.00 | yellow |
Th400 speedometer gear 42 tooth | gm # 1362049 | $10.00 | green |
Th400 speedometer gear 43 tooth | gm # 1362196 | $10.00 | purple |
Th400 speedometer gear 44 tooth | gm # 9780470 | $10.00 | gray |
Th400 speedometer gear 45 tooth | gm # 9775187 | $10.00 | light blue |
Th400 speedometer housing seal preferred | $3.00 | ||
Th400 speedometer housing o-ring seal | $1.00 | ||
Th400 10mm hold down bracket bolt and | $1.00 | ||
Th400 14 tooth speedometer drive gear | $25.00 | ||
Th400 15 tooth speedometer drive gear | gm # 8629547 | $25.00 | |
Th400 17 tooth speedometer drive gear | gm # 8629548 | $25.00 | |
One of the largest questions amongst Chevy guys is TH350 vs. TH400. Which one is better. Even though they have been out of production for decades, there is still a strong demand for them. Their simplicity and durability make them attractive to people in the LS swap community. They are certainly are both great transmissions. They share the same bolt housing patterns, and often came behind the same engine types. Whereas the TH350 would be found behind a lower performance small-block 350 Chevelle, the TH400 would be the transmission that came with the 454 SS. The TH400 also found itself in many heavy duty trucks and vans.
| TH350 | Transmission | TH400 |
| First- 2.52 Second- 1.52 Third- 1.00 | Gearing | First- 2.48 Second- 1.48 Third- 1.00 |
32 | Input Shaft Splines | 32 |
27 | Output Shaft Splines | 32 |
21 5/8” | Length from Bellhousing to Tailshaft | 25” |
The TH350 is certainly smaller than the TH400 and can usually fit into nearly any rear wheel drive Chevrolet passenger car with no problem. Tunnel modification can come into play on some of the smaller cars. The TH350 uses a mechanical kick down switch, whereas the TH400 uses an electric one. The electric kick down is much easier to set up, espescially if you are doing an LS Swap,
They do both have an aluminum case, and three forward gears. Although the gear ratios are nominally different. Neither transmission has any sort of computer control to it, nor did they use locking converters.
A lot of people claim that he TH350 has less drivetrain loss than the TH400, which means that all things being equal, the TH350 is going to get more power to the rear wheels from an engine with equal power. This is due to more rotating weight existing in the larger TH400 case. Here is a writeup on ET loss from TH350 to TH400.
They also don’t weight the same amount. The Turbo 350 weights 150pounds while a Turbo 400 weighs almost 170.
Th400 Gear Ratios
If you are going to buy a stock transmission and know it’ll fit in your vehicle, without a doubt the TH400 is the way to go. It’s super durable and will provide a long life of useful service with no modification from stock, even in higher horsepower situations.
Th400 Rebuild Kit
If you are buying an aftermarket transmission from someone like TCI or Monster transmission, I’d say go with the TH350. These folks have had decades to get all the flaws and weakness out of it. You’ll have less mass in the drivetrain and a lighter transmission.
Th400 Parts Diagram
Thank you for reading!
Th400 Shifters
Related: TH350 vs 4L60E: Comparing the Differences, Th350 vs 700R4 Differences