TH-350 strength?

[Bigcheese327]

[ QUOTE ]
a big block would eat a th350 alive unless you spend big bucks hopping it up
get a th400 and be sure to run a good sized trans cooler

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This is from another message board and I had a real tough time swallowing it. I always thought that a TH-350 could handle a mildly hopped up 396 no problem. Yes, I realize GM never used it in combination with a big block but...

What do you all think?

[Hot Rod To Hell]

I've puked several stockers behind mild SMALL BLOCKS! But I've also seen 'em hold up to some shit! If you want reliability, go with the 400. If you want cheap and easy, go with the 350! http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[BELLM]

I'm no expert but I think it would depend on how hard you drive it. If you are gonna dog it, put a 400 behind a big block. If you are not going to flog it hard all the time TH 350 would probably be ok. I would just use 400 to start with. I had an LS6 454 in a 68 Vette back in the mid 70s, had to change out 4spd as was familys 2nd car, put a stock 400 in drove it hard never a problem. Just my humble opinion. http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[chickenridgerods]

Had a Turbo 350 behind a 468 BBC in an Elky before I pulled the motor to put in front of a 4-speed in a '61 Wagon. The car was used as a daily driver (with the occasional "spirited" driving) and had the engine/trans combo in it for at least 15k miles (bought it used). The trans held up fine. I do it wasn't a Level 3, Krypton enhanced, "built" tranny either.

Of course, YMMV.

[playin' hookie]

The main problem lies with the torque of a big block. Th400 have larger input and output shafts to handle the heavier torque loads that a BBC can produce. Can you build a th350 to handle it? for sure, but just remember a chain is as strong as its weakest link.

[Fat Hack]

With a 396? Run the TH-350!

A properly built TH-350 will handle the output of a mildly built 396 all day long.

In addition, the car will be FASTER with the TH-350, as it takes less power to operate and has better ratios in most cases. I've seen lots of locals running built TH-350s behind Rat motors with no complaints.

(Now, if you're running slicks, a 5000rpm converter and a trans brake, you may be in trouble...but for a typical street/strip toy, you'll be fine!)

[Fat Cat]

Enjenjo has a TH350 in his pro street Marlin that has been there for 14 years. It is backing a 2-4bbl 460CI big block Chevy. I know I have flogged it a time or two in the time frame and it has never even gave a hint of failure. Aside from the reasons already given as to the benefits of a TH400. The TH350 has one major benefit. It uses less horsepower to operate. I would not have a problem using a TH350 behind a big block. However if I were building a race car that was going to see the strip alot I would use a TH400.

[old beet]

My buddys 32 runs a BBC 427, NOS with a well built TH350, he claims they are lighter and can be built as strong as a TH400. Low 11s ET.............OLDBEET

[AHotRod]

Cheese!
Turbo 350's are used everyday in drag-racing without a hitch!
The key to ANY gearbox is proper modifacations and assembly.
Just be certain that you have a Fresh-Trans and Convertor, and your set to go.
Glenn

[OldCarPilot]

I think like anything else it depends on how tough you build it. A general th350 will take about 400-450hp. Modify it and it skys the limit. Look at the powerglide. They are running 1200hp through these things, but they are very built. In general the th350 is not as tough as the th400. But if you put enough money in it it can easily be as tough.

[Satinblack]

Well as anything it depends on how you are driving, using, abusing it. I have a basically stock 402BBC with a stock 350 trans and never have any problems. I play around a bit but I don't abuse the thing. Besides the way some of the local so called (rat rodders) build there cars I have no worries! I blow the doors off all of them. They are lucky if there so called rod can even go a 1/4 mile with out the batterys falling out or fuel lines cracking the JB weld holding them in place http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[SamIyam]

I think whoever wrote that probably still thinks manual shift cars are quicker than automatic shifted cars!

We've come a long way in tranny development... if you have enough power to waste a TH350... you should probably have a beefed up POWERGLIDE anyway...

Sam.

[porknbeaner]

I run a T400 behind my mildly beefed 355. I broke a built T350 (bad). But it wasn't the tranny's fault. I was running an 11" torque converter (won't mention the brand) and the torque converter came apart.
You shouldn't have a problem with the T350 if its a good one to start with. They take a pretty good beating most of the time.
I don't really see that much difference cost wise between a bullet proof T350 and a bullet proof T400.
The 400 hundred weighs more and its case is bulkier. So your concerns lap over into legroom on a lot of smaller cars and in a light car the with a mild B/B the 400 would be overkill.

[Deuce Roadster]

[ QUOTE ]
So your concerns lap over into legroom on a lot of smaller cars and in a light car the with a mild B/B the 400 would be overkill.

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I love OVERKILL......... http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif


My 32 is SBC, 9 INCH Ford with 31 spline axles and a 400 Turbo.

The fact that Chevrolet DID NOT offer a T-350 behind a BBC is enough for me......they worry about warranty concerns.

The T-350 is smaller if floor/hump room is a issue.
Turbo 400's also have a larger yoke (stronger).
Turbo 400 do not have a kick down cable. They have a electric switch (neater and easier)

Turbo 400's can be fitted with a Buick 'Switch Pitch' setup. It is a two stage stall convertor. Mine is 800/2800.
Works great in a light, somewhat lumpy light car http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif (350-roller cammed 2240 pound Roadster)

http://img53.photobucket.com/albums/v163/DeuceRoadster/MVC-013F.jpg

http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif