Looking for information on the pros/cons of both. I am needing to upgrade and looking for advise. I've got one in mind already just trying to see what everyone's thoughts are.

 

Nobody have any info?

 

I guess the cons are if you exceed the strength of either one
A 400 is heavier, stronger, and cheaper to make stronger
The 350's can be made strong
I guess it depends on what you want to do
I think the 350 has a 2.52 1st gear as opposed to the 2.48 on a 400
some of the super stock guys used to like the 350's

 

Bama. Stay with a 400. The transmission is far superior to a 350.

Gerg

 

That really depends on how much power he is putting through it, I have quite a few out there taking 600-700 horsepower with no issues. Intermediate Sprag race, Extra friction in the Directs, Dual feed, 4L60E center support, Billet input shaft along with a quality rebuild goes a long way on a TH350.

 

are you planning on beating the **** out of it with high horsepower or just a cruiser

 

Yes, you can do a lot to improve the TH350 to hold up (and I have done pretty much the same as mentioned above), but it is far cheaper to start with a TH400 and have it hold up to some high horsepower and/or aggressive driving and last. With the late Borg Warner Hi-Energy clutches and bands, TransGo 400-1, -2 or -3 (or feeding both halves of high gear someway), 34 element intermediate sprag, TF 727 .106" snap ring for the intermediate clutch pack, and a couple of other things here. This will hold to an easy 750 - 900FWHP with the right torque converter. Any good transmission builder should be able to do this, or this is something that you could do with all of the information that is now available on the internet.

 

400 is a good unit. Only complaint about them is upgrade the sprag or don't spin on the 1-2 shift or you'll roll the sprag