Th350 vs th400

[1979blkchevy]

Hello everyone I have been reading the forumn about th350 and th400 because i have herd that th350 isnt good for mudding trucks and towing stuff and then a couple of my buddies said stay away from th400s!!

So anyone who has had experience with theses trannys please feel free and let me know your opion on how good and strong they are and ect thanks in advance

[nekkidhillbilly]

find new buddies

[truckincurt]

whats there reasons for staying away form the 400

[Keith Seymore]

The only reason for staying away from a 400 (that I can think of) is that they suck up more horsepower than a TH350.

If you are on the ragged edge in a timed competitive event, like NHRA drag racing, there might be an advantage to changing.

However, for the street or some activity where it's purely subjective, the TH400 is a heavier duty trans and you are less likely to tear it up in a heavy, high performance vehicle.

The stock TH350 also has a little bit steeper first gear compared to the TH400 (2.52:1 first vs a 2.48 first, respectively).

K

[1979blkchevy]

Originally Posted by Keith Seymore

The only reason for staying away from a 400 (that I can think of) is that they suck up more horsepower than a TH350.

If you are on the ragged edge in a timed competitive event, like NHRA drag racing, there might be an advantage to changing.

However, for the street or some activity where it's purely subjective, the TH400 is a heavier duty trans and you are less likely to tear it up in a heavy, high performance vehicle.

The stock TH350 also has a little bit steeper first gear compared to the TH400 (2.52:1 first vs a 2.48 first, respectively).

K

thanks for your reply im searching the forumns to learn more now

[truckincurt]

yes the 400 sokes up a tuch more power but with more clutch discs in the transmision they are hader to brake so is there any bennift to switching kinda more clutch disc can handle more power so if ur bulding alot of power id switch

[1979blkchevy]

Originally Posted by truckincurt

whats there reasons for staying away form the 400

they couldnt give a reason

[1979blkchevy]

Originally Posted by nekkidhillbilly

find new buddies

lol the funny thing is they couldnt tell me why lol i thought that to though

[old Rusty C10]

Ive owned both th 400 and th 350 trans. the th350 i can tare up in a year the th 400 takes longer..I tow all kinds of junk and haul stuff way to heavy for it and the th400 is pretty well bulletproof

[nekkidhillbilly]

th400 was in 3/4 and 1 tons for a reason

[Red84C10]

The Th350 in my 84 lasted 250k before it went out.

[Benelli]

Shift kit in either of them and they should last you a good while.

[slugish]

Originally Posted by Benelli

Shift kit in either of them and they should last you a good while.

x2

[Scootin 81 C20]

Mine has a TH400 in it and it is good, but I think GM could've improved it by adding an overdrive from the factory. Do they make an add-on overdrive for the TH400?

[asphaltburner]

Yo! I'm quite satisfied with the TH350 in my 325-350hp '76 Camaro, and the TH400 in my '78 (same engine) K20 longbed.
35,000+ street/strip on the Camaros',...the truck is just getting started back on the road.
The Camaros' TH350 and 2.79 rear gears make it quite the road car with the power to turn those low gears. I shift it manually down a gear to pass and get about 15.5mpg ruling the road.
The FRANKENTRUCK doesn't do as well with the TH400, even with 33" tires,...with 4.11 front/rear gears, the lack of an overdrive causes the 350V8 to run at about 3200rpm at 75mph, but damned if it doesn't accelerate quickly off the line! I expect to lower it's axle gear ratios to 3.42.
Both trannys lack overdrive but are tough as nails!
Todd.