[Skeeveman]

Just finished putting the front end together and lined it all up. Koni/QA1 shocks, Moog 5392's, AFCO LF ball joints, and all the rest was Spicer pro. grade parts... Never drove better! That was saturday. Took it out for a spin today and put some petro in the tank, by the time I got back from a 15 minute drive I had no first gear, and second and third was slipping like none other.

It actually started saturday morning, right before I aligned it. It wouldn't go into gear, put a quart of fluid in it and got it to grab. What was on the stick smelled burnt, so I knew it was a time bomb. It had forward gears, but first wouldn't do anything, just sat there are revved like there was a load on it. So I got to rolling about 5mph in second and dropped it into first, made a big clunk and popped into gear, like a stuck valve or something. It worked fine until today. Now it just doesn't move that damn hard at all when you get in it, just sounds cool, lol.

The trans is a 350 with about 2000 miles on it total since rebuild, about 700 of them have been behind the 540. The converter is a 3500 hughes. I'd love to put a 6 speed behind it, but just can't afford that right now. I need to decide whether to rebuild the 350 and and beef it up, or use a 400. I want to be cost conscious, but also want to hold up to the power as well. Jakeshoe has some good threads on nastyz28.com regarding the performance rebuild of 350/400 trannys. I'm thinking of just buying the parts and stacking out one myself.

I guess I'm wondering what you guys would do in this situation? How good of luck have you had with a 350 behind 600hp/650ft lbs? Should I find a 400 and forget about it or what?

 

[Dave427]

I like 350's , get it rebuilt then you won't have to redo your driveshaft. We had one behind a 600 HP 540 with no problems.

Dave

 

[curley8788]

i agree with the above. my buddy has a 454 with 575 hp and his th350 lives behind it no problem. you just need someone skilled to build it.

 

[65lkey]

I rebuilt my 350 for a senior project, it wasn't that hard if you have all the tools. and the guy that helped me said that he has seen many 350's behind many high horsepower. My motors only pushing maybe 400 at the crank but I've put that 350 through a lot.

 

[DragRacer]

I run a home built TH350 behind my 445 SBC, but then again it only dynoed at 672HP / 616 lb-ft TQ. It should make about 30 HP / 20 lb-ft more than it dynoed after a few changes.

With just a few changes, they can be made to live. If you need a transbrake, I would move to a TH400.

 

[Chris Stanwyck]

I like 350's , get it rebuilt then you won't have to redo your driveshaft. We had one behind a 600 HP 540 with no problems.

Dave

Agreed.
As well more power to the rear wheels and less weight.
Couldn't break a well built (milton Transmission) 350 behind a nitroused 468 a few years back. High tens on a regular basis. :yes:

 

[350_Malibu]

My TH350 went south 4 weeks ago similar to yours after it had sat for a year while I finished suspension and brake builds on my TH350. Every time I moved the car it had a real hard time getting into gear, especially reverse. I had it rebuilt with upgraded parts, shift kit and Automatic valve body for street/strip use. The builder who is friends with my father in law said it would handle an easy 600-650hp. If you can get your hands on the right builder they can make your TH350 handle what your throwing at it.

 

[Skeeveman]

Yeah, I think I'll be rebuilding it. Looks like I need to get out to the shop and finish wiring it up and getting the work bench built so I have a good space to do it. Jakeshoe has a pretty nice 350 modification guide over at nastyz28, I will be reading over that several more times. I've never dove into a 350 other than fluid/filter changes and shift kits... but it needs to be something I can do if I want to keep hot rodding I think.

I think it was a combination of the heat and torque that killed the trans. I opted not to put an external cooler on, and this time I will. I'll be putting one inline with the cooler in the aluminum radiator, as well as a trans temp gauge.

 

[Skeeveman]

Well, good luck has struck again... my old man made a phone call to a buddy of his in Alabama asking if he had any 400 cores we could have to rebuild, and he had a spare 400 freshly built, that hasn't even had fluid in it that I could have for free! He said it's been hopped up, who knows what it has, but hey, it's free! And this guy's pretty damn straight forward with what he's got, so I'm sure it'll be good. Looks like I need to find a 400 yoke.

Also, anybody know of a good place here in the north Atlanta area I can have my converter flushed? I may just send it back to Hughes for a freshening/restall, haven't decided yet.

 

[baloo28]

Sounds like you got it solved, but if you want/need a 350, I got one down here in Florida....