th400 vs th350

[78sik ick]

I have a th350 that was built but is starting to give out. Just wondering if I would be better off uping to a mild th400 or get the th350 rebuilt again with even stronger parts. I'm making approx. 475-500 at the wheels. I have a builder who will do it for me for the price of parts and a case of beer. just looking for your 2 cents

 

[bill]

I have a th350 that was built but is starting to give out. Just wondering if I would be better off uping to a mild th400 or get the th350 rebuilt again with even stronger parts. I'm making approx. 475-500 at the wheels. I have a builder who will do it for me for the price of parts and a case of beer. just looking for your 2 cents

BOP th400 will handle a lot more power out of the crate. May require more modifications to make it fit, but might be worth it. Takes a bit more power to turn a 400, but I dont think you will notice....

 

[78sik ick]

Thanks for the reply, do you have any idea how much more power, like 10% more than th350 like 10hp? Do you have any idea?

 

[Blue86Monte]

What is in the TH350 now? I have one behind my SBC making around 550-600 to the wheels without a problem. TCI synthetic clutches, hardened sprag and drum, hardened shaft. Yes is it not as stout as a TH400, but you already have a TH350, and the drive shaft to go with. Heck, we are even putting a trans-brake on the car for next year. This is my trans. Clutches as stated above, upgraded sprag and drum, street-fighter valve-body; PTC converter if it makes any difference.

 

[78sik ick]

I'd have to double check but I know that it has tci clutches for sure, I believe stock shafts. Just wondering how much those upgrades cost compared to getting a th400 for $200 and having that built up a little.

 

[Blue86Monte]

In the long run you will be ahead with the TH400. Do you have plans for more power? That would be the main factor I would look at. If your planning on more power then go TH400, but if you are about done then stick with the TH350...

 

[78sik ick]

There is always more power down the road lol but with a whole new motor.... i just got a 4 bolt block with plans of a fully forged roller cam 383 hopefully around 650hp.

 

[Evan11]

A 400 is said to use about 18 Hp more to run over the 350. But with that kinda power, a 400 would be adequate.

 

[Blue86Monte]

A 400 is said to use about 18 Hp more to run over the 350. But with that kinda power, a 400 would be adequate.

Data to back up your statement?

 

[-83MONTESS-]

A 400 is said to use about 18 Hp more to run over the 350. But with that kinda power, a 400 would be adequate.

I found it online awhile ago that a TH400 actually takes 7-9% compared to 5-7% of the TH350 but a stock TH400 is good up to 600hp. It was in a Hot Rod magazine. I would have to do some looking to find it but I dont think you will notice the change.