Which tranny would be best

[JGood]

My truck originally had a 700r4 in it and am wondering which tranny would be best for my application as I just pulled my 400 out which had no reverse or high gear left in it. I'm just wondering If I should stick with it or put something else in and in order to put a 700r4 back in I need a bit of a rewire.
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[wraprail]

T56. Best
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[superwade57]

More info. Rear gears motor build primary use tire size
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[superwade57]

Originally Posted by wraprail

T56. Best
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X2 that's what I got
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[JGood]

She's still stock with a 350 bit as for rear gears I'm not sure never had her opened up and eventually I would like it to be a nice street able driver that will get up and go
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[canadian trucker]

Originally Posted by superwade57

x2 that's what i got
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x3

[Mikec10]

A t56 is nice but they are a little pricey, I run a 5 speed nv3500 out of a late 90's s10 behind my cammed 350 and i beat on it a lot and its held up just fine. It was about 200-300$ on craigslist. Whatever you do though, DO NOT get a 5lm60 which is found in like 88-91 fullsize gm trucks.

[andrewmp6]

If you want a auto trans the 700r4 built right will last a long time,A stick depends your budget and power what you can use.

[Tx Firefighter]

All these guys are spending your money here by telling you to convert to an expensive overdrive standard trans. Now you'd be looking at installing all of the clutch setup along with the transmission.

Lets look at it in a more budget and simplicity perspective.

700r4 is a good trans. You get the overdrive and your truck is already set up for an automatic trans so no added expense of clutch pedal and all of that.

TH350 is a great transmission. It's also an automatic so the swap would be easy. Downside is you don't get overdrive gear. But, a great number of these trucks came with 2.73 and 3.08 gears so you wouldn't even need an overdrive anyway. They drive great on the highway without overdrive.

TH400 is a super heavy duty automatic trans. Again not an overdrive though. Upside is your truck is already set up for one so the swap would be a direct remove and replace job. Using a turbo 400 behind a a stock 350 is a bit like killing flies with a bazooka though in that the TH400 is a bit overkill in strength for a stock small block.

Mainly, you need to determine what your current rear gears are and if you feel the need for overdrive or not. Anything 3.08 or lower (numerically), I'd skip the overdrive. 3.42 or high ( numerically) I'd go with the 700r4.
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[Rubble]

I would agree with firefighter,stay with the auto.It will be probably be the cheapest way to get your truck back on the road.A 700r can be built up pretty decent too.If your diffs are like he said low 3s or high2s you might not even need OD. As far as the standard granny's,I have a A833 behind a 6.2 in my K25. Nice combo,I don't tow with it,so it works fine.
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[JGood]

Ya I must have a higher gear ratio because when I'm ripping down the highway with the turbo 400 she just screams so overdrive probly would help. My only issue is that in order to put the 700r4 back in my truck I need to find a wiring harness because the previous owner had swapped it for a turbo 350 and just hacked all the wiring out for the 700r4. But I think I'll just toss a 400 back in and let her scream or else droop the gears and toss a possi in with the right gear ratio
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[wraprail]

Originally Posted by superwade57

X2 that's what I got
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Originally Posted by canadian trucker

x3

Best upgrade I have ever made to any car or truck I have ever owned.
Driving was never so much fun. Plus my C10 Brick goes over 100mph very easy

Originally Posted by JGood

Ya I must have a higher gear ratio because when I'm ripping down the highway with the turbo 400 she just screams so overdrive probly would help. My only issue is that in order to put the 700r4 back in my truck I need to find a wiring harness because the previous owner had swapped it for a turbo 350 and just hacked all the wiring out for the 700r4. But I think I'll just toss a 400 back in and let her scream or else droop the gears and toss a possi in with the right gear ratio
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Look inside the glove box for your gear ratio.

[tucsonjwt]

If you drive mostly in the city a manual transmission gets old quickly. I have a 454 SM465 in my current 83 C20 and wish I had the drivetrain in my 73 454/TH400. That 73 was smoother and faster than the 63 Vette I owned as a teenager. No overdrive, but in city driving overdrive does not help you much.
Since I have only had 3/4 ton pickups, gas mileage is only 9-11 mpg in the city no matter what gas engine/trans combo you have.

[Want2Run]

Originally Posted by JGood

Ya I must have a higher gear ratio because when I'm ripping down the highway with the turbo 400 she just screams so overdrive probly would help. My only issue is that in order to put the 700r4 back in my truck I need to find a wiring harness because the previous owner had swapped it for a turbo 350 and just hacked all the wiring out for the 700r4. But I think I'll just toss a 400 back in and let her scream or else droop the gears and toss a possi in with the right gear ratio
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With my experience with a 700r4 overdrive was mushy as could be, and it burned up quickly and when I bought it, only had 6,000 on it but I have friends who sware by them. Id go with the 400turbo or a 350 turbo, I have currently a rebuilt 350 turbo with a tremco shift kit and a b&m holeshot convertor runs great on the road. stock rear end gears in my 85 C10 also. slightly built 350 thou.

[andrewmp6]

A bone stock 700r4 depends the year on how they act.If you get one built up they will take a beating.A friend of mine has a jeep wrangler with a 4bt cummins with a 700r4 built to handle it.Hes had that trans in it going on 3 years soon daily driver no problems at all.

[74 stepside]

Its going to be cheaper to rewire the 700r4 than it is to rebuild the t400. Also, do you have 2 different driveshafts? They will be different lengths and different size yokes when swapping..

[wraprail]

Originally Posted by tucsonjwt

If you drive mostly in the city a manual transmission gets old quickly.

I know many many people (including myself) that would disagree with this statement.
My current truck had a turbo 350 and it was Boring to drive.
Now with the T56 it's a pleasure to drive, even in LA traffic.

My last car (an 05 Cadillac) had a 6 speed and it never got old.

[JGood]

Originally Posted by 74 stepside

Its going to be cheaper to rewire the 700r4 than it is to rebuild the t400. Also, do you have 2 different driveshafts? They will be different lengths and different size yokes when swapping..

I custom built my driveshaft to be a one piece with no hanger bearing to fit the 400 and I'd probly do the same depending on the tranny I use
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[JGood]

Ya I'm not big onThe manual tranny but it has its place
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[B Barber]

Unlike a lot of people, I happen to love a 700R4. A TH400 takes around 40 HP to operate, a TH350 takes around 25, and a 700R4 takes about 14. Plus, you get a 4th gear, and overdirve on top of that. So its like adding 2 more gears. They can be very well built, but you have to get the correct one to start with. Mine is out of a 93 Trans Am, with the upgraded case half. I am running a full manual reverse pattern valve body, a billet bellhousing, billet input and output shafts, billet converter, 555 boost valve, 6 pinion front planetary, 5 pinion rear planetary, plus other upgrades. Mine is guaranteed for 1000 HP. Long story short, current technology has greatly increased the potential of these transmissions, but it is not cheap. I have about 6K in mine. If I ever have to replace it, I will be going with a TH400 and a Gear Vendors Overdrive setup.