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Discussion Starter · #1 · (Edited)
What can a torbo 350 swap to?

The 69 impala has been WELL looked after. Regular tranny oil changes. With the 383 stroker torque and an open diff 373 I'm hoping she'll take it a wee while anyway. The guy that had it really babied it, put a tranny cooler out front,That cant hurt. Thoughts

Given the things I've heard I'm wondering what junkyard trannys to look at that might swap into my 69 impala right away while I'm engine changing and last longer? Heck maybe even something with an OD? what about trannies in S10's. Its a column shift if that matters much
 

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Old School Motorhead
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Buy a spare core, rebuild it, and keep it as a spare. Then, run and run some more until the old one gives out, swap, and rebuild the old one for a spare, etc etc. I've got a spare drivetrain (engine, trans xferr case) for my 82 K10, it comes in handy.
 

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Discussion Starter · #5 ·
XNTRCI-T said:
I was told by the race tranny guy who built my TH350 that a stock 350 is only good for about 300 ft/lb of torque.

I would tend to agree yet when you read down the spec sheet here to engine tranny combos you can certainly see more torque coupled to the turbo 350. Actually I had an 89 turbo 400 buckle under 2/3 the torque and 1/3 the mileage on this car. I wonder if there isnt saomething to be said for the phrase "AH THE GOOD OL DAYS"
http://www.oldride.com/library/1969_chevrolet_impala.html

like another example is the 426 or 440 chrysler in a 4200 pound car with the little 727 torque flight in there. Nowadays they'd build twice the size at three times the price and it would pack it in in half the time. All the chrysler auto trannies packing it in in mini vans with half the motor and half the weight
 

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sooper said:
like another example is the 426 or 440 chrysler in a 4200 pound car with the little 727 torque flight in there. Nowadays they'd build twice the size at three times the price and it would pack it in in half the time. All the chrysler auto trannies packing it in in mini vans with half the motor and half the weight
Not really,
They are still using a derivative of the 727 behind the Dodge Cummins diesel engines in the 1 ton trucks.
They added a lockup converter, an OD section to the back, did a few upgrades and they are trying to keep it alive behind the huge torque these engines make.
 

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Discussion Starter · #7 ·
jakeshoe said:
Not really,
They are still using a derivative of the 727 behind the Dodge Cummins diesel engines in the 1 ton trucks.
They added a lockup converter, an OD section to the back, did a few upgrades and they are trying to keep it alive behind the huge torque these engines make.
Ya and in its current form I wouldnt say its doing as swimmingly as yester year. I remember going into mopar dealerships in the last decade and the salesman telling me outright "If you can at all drive a standard stay away from our autos". You didnt hear that about that basic form tranny 4 decades ago. You just saw it peeling loads of rubber in cars that rival some of todays trucks in weight and as for power the 440 2x6 and the hemi made torque,yet not a worry. When I see numbers like the turbo 350 only handling 300 ft/lbs of torque I say maybe as of late but if your talkin about one from the sixties your talkin in the same terms as a torqueflight from the sixties which is the raw un-chinesed version. The GM spec chart I pasted up top says 380 ft/lbs and you know GM is going to be modest in attemt to ctoa. I took my 67 A833 apart after fourty years of hammering. he11 even when it comes to standards I wish the guts of my 3/4 ton dodge tranny looked as well made. I looked in that thing and sure everything was bigger but not better,crisper cleaner, put together with care. Not even close
 

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I don't really recall the GTX's, Cuda's, Darts, Roadrunners weighing in excess of 6000 lbs and hauling 10,000+ lb payloads or having 650 lb/ft of torque despite how it seems from the legends and through the rose colored glasses of memory (blinders).

The TH350 is much more equivalent to a Chrysler 904, not the 727. The 727 is more equivalent to the TH400.

Th350's with mods can handle 700+ HP/TQ.
I have quite a few doing it for seasons at a time.
 

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jakeshoe said:
Not really,
They are still using a derivative of the 727 behind the Dodge Cummins diesel engines in the 1 ton trucks.
They added a lockup converter, an OD section to the back, did a few upgrades and they are trying to keep it alive behind the huge torque these engines make.

oh..... Mopar did more than a few upgrades. Stuff they should have changed 10 yrs ago when the trans is behind the diesel motor .. IMHO

at least they figured out that they needed steel planetary units with 6 pinions, better ratio on the apply arms , stronger rear bands, wider thrust washers ... it is still a basic 727 in the front section :thumbup:

:pimp:
 

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Discussion Starter · #10 ·
jakeshoe said:
I don't really recall the GTX's, Cuda's, Darts, Roadrunners weighing in excess of 6000 lbs and hauling 10,000+ lb payloads or having 650 lb/ft of torque despite how it seems from the legends and through the rose colored glasses of memory (blinders).

The TH350 is much more equivalent to a Chrysler 904, not the 727. The 727 is more equivalent to the TH400.

Th350's with mods can handle 700+ HP/TQ.
I have quite a few doing it for seasons at a time.
Any basic upgrades one might suggest while the engines out this winter anyhoo?
 

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Discussion Starter · #12 ·
SSedan64 said:
No doubt thats a sweet build but for nominal street use is there something kind of in between what our good member Jakeshoes does and just leaving it alone? Like for instance if it was a manual I could go all the way from easy push tender diaphram clutch to all out bananarama. BUT there is things still borg and beck, mid line performance, yet street easy, you know a happy mid ground. Not saying Jakeshoes isnt worth every ounce of bucks and time, just wonder if a saturday take momma to the A&W type guy needs all that?
 

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My build addresses the weak points of a TH350.
I build them the same for any performance application.

This isn't an expensive build sheet. $250 worth of parts from my shop.
It addresses the weak third gear clutch hydraulics and adds clutch capacity, adds support at the sun gear, replaces the failure prone intermediate sprag race.

Anything less during a rebuild would be a shortcut.
 

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use a th400 save the money later.

I just burned the clutches out of my ,"thought to handle H/P TH350" one good launch from my 400+ H/P Monte with 10.5 slicks, I smoked the low end clutches, instead of trying to repair a pony to carry a horses load, I went with the TH400, bigger yolk and better U joints. Just my opinion though.
 

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Discussion Starter · #15 ·
strokedout said:
I just burned the clutches out of my ,"thought to handle H/P TH350" one good launch from my 400+ H/P Monte with 10.5 slicks, I smoked the low end clutches, instead of trying to repair a pony to carry a horses load, I went with the TH400, bigger yolk and better U joints. Just my opinion though.
ya, but ya gave about 30+ hp to that 400 as I understand it. guys here are running 1/4 mile with some pretty wheelie pulling stuff on little powerglides, rebuilt of course
 

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strokedout said:
So does that mean I am loosing 30+ H/P using a TH400 compared to a TH350 or Powerglide?

No,
That's a myth that continues to get spread even by supposedly knowledgable trans guys.

I have yet to have anybody prove it's true with dyno testing, drag strip ET/MPH difference or otherwise.

Our own experiences at my shop are that a back to back swap between a TH350 and TH400 using the same converter will not make any repeatable ET/MPH difference. I've seen .04 difference on a fairly consistant car, but that could have been air density, tune, or anything.

In theory there would be a HP difference but it would not be a set number, it would vary depending mostly on the rate of acceleration.

In other words a 13 second car would maybe be 1 HP difference, a 10 second car might be 10 HP difference, and a 8 second car might actually see the 30 HP difference claimed but in an 8 second car, a TH350 would be short lived.
 
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