[Andrew7dg]

I was wondering which one people perfer in transmittions even though they are sort of simmilar.

I was also wondering what rear end gears have people have luck with those transmission? I want to put this in an olds 84 behind a 350 engine. I would like good traveling on the high way but good pull from the line. Is this even possible with this transmission. And what kind of tourqe converter?

is this too broad of a question?
thanks for your help

[drewhelm]

The major difference between the two is the strength. The TH350 is a very good performer if built right and will last a long time, not to mention they are CHEAP! They can be built to handle quite a bit of HP, however the TH400 will handle about as much HP and Torque as you can throw at it. For a mild street/strip motor a built TH350 will be more than adequate.

As far as rear gears go a good "middle of the road gear" is the 3.55 or 3.73. You will get decent pull off the line and depending on tire size will turn around 3000 rpms at 70. You would want a taller gear if off the line performance in your primary concern ie. a 4.11. For more highway manners you could move down to a 2.73 or 3.23.

It all really depends on your car and driving characteristics.

Personally, I am running a 560+hp Pontiac 455 with a TH400 trans, Transgo shift kit, and a 3.23 posi. My motor makes enough low end torque and makes all it's power below 5500rpms, so the 3.23 is perfect. And it cruises at about 2600 at 70.

[BstMech]

The pontiac 455 is a torque monster, But I heard you need case savers with the turbo 400.

[bonuts]

One difference I have found is that the th350's suck up less power, than a th400. Not to mention the cost issue, th350's are cheap to build a decent one. As for the gears question, if your going on the highway 4:11 are brutal, unless of course you build a 700r4 tranny... go lower with gears 3:73, 3:23, 3:08 may be a little to much though.


bonuts