what makes the TH400 better than the TH350?

Answer 1

I own a transmission shop, and would like to put in my 2 cents worth. A turbo-400 is in fact a stronger transmission when it comes to the case. The internals aren't much different. The clutches are the same when measured with a micrometer. I drag race, and I would rather build a 350 any day over a 400. Reason being; the ratio in the gearing. A 400 is much more higher geared, and was put into cars, and trucks that had a high torque engine such as a big block. Most people that race use the Power-glide or an aftermarket transmission, and then after that they use the turbo 350. The only reason I would use a 400 would be because I just wanted to keep my car as it came from the factory. If you talk to anyone that is in the transmission business, they will tell you to go with a 350. The reason is to cut down on weight, and a 350 can be made bullet proof a lot cheaper than a 400. The 400 takes up more space, and out weighs the 350 by probably 50 pounds. You can even get a lock-up stall converter for a 350 and a 700R-4. As far as the 400 being better, I would have to disagree with that statement. We build them all the time, and the 400 is crap, when you compare it to the 350. It's heavy, high geared, and more expensive to make bullet proof, so why would any one want to use one is beyond me.
Glad to help out, Good Luck!!!

Answer 2

the TH400 has better, stronger gears and is much more durable. Not to say that the TH350 isn't durable...it's also widely used in drag racing.

Answer 3

The internal parts plus the trans case itself are built much stronger in order to handle higher horse power and torque.

Answer 4

turbo 400 is considerably stronger than the turbo hydromatic 350

Answer 5

It's a stronger transmission and will take a lot more abuse.

Answer 6

It is 50 better.