Yes, you can. As previously stated, you would need to change the output yoke - and you would need to move the crossmember back 4 inches to fit the TH400 mount.
Both transmission pans have 13 bolts, but they have a different shape. The TH-350 uses a square pan, with one corner cut off. The TH-400 uses an oblong-shaped pan with one side having a "hump" in the pan and one side is curved while the other two sides are straight.
TH-400 transmissions are three-speed automatics, with a 2.48:1 first gear. Reverse gear is 2.08:1 and third gear is an even 1 to 1. Turbo 400s use three tail shaft lengths; the most preferred units for a GM swap would have the short 4-inch tail shaft.
Overdrive. The 700R4 has an overdrive while the TH350 does not.
It's also one of the chepest mods per performance you can buy! A higher stall speed torque converter DOES NOT add any horsepower. What it does, is move the engine rpms up higher at launch, so that you have more horsepower per mile per hour. Just like when you rev a stick shift car up higher for a quicker launch.
You didn't do a swap from a long TH350 to a short Th400, More likely a short TH350 (6" tailhousing), to a short TH400 (4" tail). In that case the Th400 is about 1/2" longer.
The TH350 is an automatic shift, three-speed transmission. It is widely considered to be one of the greatest of automatic transmissions ever built.
Measure the transmission case with a tape measure. The Turbo 350 case measures 21 3/4-inches long from the front of the bellhousing to the rear of the case. Do not include the tailshaft housing which bolts to the rear of the case. The Turbo 400 measures 24 3/8-inches long from the belllhousing to the rear of the case.
Unless it has a manual valve body it won't shift without vacuum until very high RPM's. Besides the fact that when you disconect the vacumn line the line pressure goes to full which can wreak havock inside the transmission, I don't think that it will shift into high gear.
selling it as a good unit and with a "it will work" or your money back warrantee, it should be worth $150-200. There are many shops that sell a stock rebuilt TH400 for $600.
The TH400 is much stronger, but it doesn't have overdrive and the first gear is only 2.48:1. The 700R4 has an overdrive gear (0.7:1), and a 3.06:1 first gear, but it's not as strong. So it depends on what your using it for and how much power you have.
The 4L80E is just a longer, heavier, overdrive version of the TH-400. It uses the same first three gear ratios but adds a 0.75:1 overdrive. This means that with a 3.55:1 rear gear, the overdrive drops the effective rear gear ratio to 2.66:1. This makes the first question more about torque converter selection.
Figure most "consumer" shops are going to put about $300-$400 materials, and about $200-$400 labor.
Instead of a linkage or cable, the TH400 uses an electrical switch that is most often mounted on the carburetor. The factory used a switch located on the carburetor or on the throttle linkage under the dash that at WOT supplied voltage to the transmission.
The TH350 from the mfg. indicated it was designed to handle 350tq and Gm soon realized it would handle much more than originaly designed for. same with the th400 it was meant to handle 400.
The Street/Strip 700R4 is good for about 550 hp maximum, but with the HD input drum it is good for about 625 hp max.
They are stronger than most want to admit. Good luck with your decision! Neither a stock TH-350, TH-200-4R nor a TH-700R4 will support 500hp and associated torque as originally built. . But a TH350 will support 500hp without having to replace any hard parts.
The TH400 is an automatic shift, three-speed, longitudinally positioned transmission. It is widely regarded to be a supremely durable and legendary transmission. The TH400 is conservatively rated at 450 ft. lbs. of input torque.
They are, for the most part, interchangeable on the same vehicles; however, you would normally find the TH400 in larger engine applications because they are able to function more reliably at higher engine rpms.
GM Turbo 350 and 400 Transmission Measurements27 11/16 in.
TH350. Best transmission choice, hands down. 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 aluminum case Powerglide transmissions.
The internals are exactly the same between a th350 and th350c. The only differences are the input shaft and pump cover and they are only different in length to accommodate the lock up converter. I've converted th350c's to non lock up by using an input, pump and converter out of a th350.
A good TH350 is going to cost more than $200. I spend more than $200 on parts to rebuild one (stock) and I get good pricing on the parts since I'm a transmission shop. This doesn't upgrades, labor, shop overhead, etc. The days of having an automatic transmission rebuilt properly for $200-400 are done.
When the throttle linkage reaches a specific point, the cable triggers a mechanical detent valve inside the transmission--allowing it to shift into a lower gear. The Turbo 400 uses an electric switch to trigger a detent solenoid on the valve body to produce the same effect.
Amsoil ATF works with a Turbo 400. The high-quality ATF can withstand the intense pressure in a Turbo 400 transmission. As such, it enables it to perform and also offers optimal protection. You can also use Mobil 1 automatic transmission fluid.
Need help finding what you are looking for?
| TRANSMISSION FLUID CAPACITY |
|---|
| Transmission (w/ Stock Pan) | # of Quarts |
|---|
| GM TH350 | 4 |
| GM TH400 | 6 |
| GM Powerglide | 4 |
You can use a 700r4, besides the TV cable, and wiring up a torque convertor lock up switch, you would need a VSS for the ECM and your speedo. I would stick with the 4L60E like others are saying though, if you can afford it. They are a little bit stronger.
Vehicles Equipped the 700R4
- Blazer: 1982-1991.
- Caprice: 1982-1992.
- Corvette: 1982-1992.
- Camaro: 1983-1992.
- Suburban: 1984-1992.
- Astro Van: 1985-1992.
- S10 Blazer: 1989-1992.
- S10 Pickup: 1989-1991.
The four-speed Turbo Hydra-Matic 700R4 was introduced for the 1982 model year for use in Chevrolet/GMC vehicles. In 1990, the Turbo Hydra-Matic 700R4 was renamed the 4L60.
