The TH (turbo-hydramatic) 700R4 was developed for use after 1982 in GMC and Chevrolet cars and trucks.

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Is the 700R4 interchangeable with the Turbo 350?

Probably I will get nailed for this one, but here goes.

I have a 1986 Chevy K20 Pickup. It originally came with a Turbo-Hydramatic 350 transmission. It has a 700R4 installed now, which is shot. Will I be able to re-install a T350 with no other wiring or tubing modifications? Should I just be safe and find another 700r4 and throw it in?

Off computer topic I know, but hey do I care? There is a big knowledge base out there.

Regards,

Frank

Answered! View the answer I have this problem too

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It's definitely a hardware problem ;-)

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Got a 77 Malibu with build 305 an 350 turbo can I change trans over a a 700r ?? Or a 400turbo??

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My advice is avoid a transmission that utilizes a Throttle Valve Cable. The plastic buckle on the end breaks, Doesn't matter what gear you're in, how fast you're going, or how far you drive with the cable not attached. You burn clutch material and it wears the gear down no matter what, more than likely resulting in a complete failure of the transmission. I've been through 2 in my 89 GMC c1500 305 slx, can I put a turbo 350 or 400 in my truck without doing anything other than the swap itself and the fluid change?

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I put a 350 turbo in place of a 700 with the 9 inch tailshaft.i put the 700 tailshaft on to use the electric Speedo and the shaft sticks out of the back several inches any solutions?

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This URL seems to answer your question. Good luck. Ralph

http://www.hotrodders.com/forum/can-i-pu...

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Read all the way down to get the speedometer info. Ralph

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nice research +

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Yeah, great info, thanks. My speedo is about 5 mph off since it must be the old style. So, whichever tranny I find cheapest and quickest will make it in there. Also, it's for sale :) https://accounts.craigslist.org/post/shw...

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350 hydromatics come in 3 tailshaft lenths (sic) 6 inch 9 and 12 they have the same output spline flexplate bolt pattern and engine mounting pattern to swap out a 700 r4 you need a 9 inch you will have to move the transmission support forward several inches .this causes a little alinement issue with the shift shaft in some applicatinos but it will work other than having either not enough positions or too many on the shift quadrant , and you better hope that you are swapping out an early 700 with a speedo cable as some later units(i think) had a speed sensor that means finding a new tailshaft cone and gears to drive the speedo cable there is a cable operated shift control on both transmissions and a vacuume operated pressure control on the 350 that warrants some understanding .also late 350s had a locking torque converter(adds an electrical ciruit) in an effort to improve fuel economy (but they also cut the weight out of some of the internal rotating elements at the same to reduce weight)some would say and reliability i'd call it an easy swap for any back yard mechanic certainly much easier than what you need to know to repair cars of only one decade later

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Good information thanks for sharing.

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you will need to get a different tail shaft, the th350 is shorter, and to be honest, you want to the 700r4, get it rebuilt if you have to, the difference in fuel economy will pay for the cost of the transmission in time

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i got a 57 chevy with a 4 speed now 0n a 350 motor & want to put a 700r4 in it. what will that take

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i have a t700 changing to a t 400 what do i do with the 4 pin wire connector from the 700?

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I have a 1969 powerglide tranny in a impala. I want to go to a t350 tranny its an older one they look about the same size will this swap go smoothly?

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I have a 88 Tbi 5.7 pickup that I backdated to th350 from 700r electric speedo I just wanted to state that the tail shaft housings will interchange and all you have to do is nab the speedo gear off of the 700r I did so with a lack of tools so I used a 2x4 and a hammer but needless to say it worked and that's the only snag I ran into for the back date except the crossmember which I had to notch and drill a couple holes in the frame..easy peasy I pull heavy loads and will never own another 700r again...oh one more thing..the vacuum...tee off of the map sensor from the manifold port on the back side of the Tbi and you will be fine be sure to use a steel line.. also I spliced the kick down cable with the TV cable so it would work with my brackets..cheap but effective... the 700r TV cable housing will not fit the 350 turbo all you need is a cable stop from any hardware store and switch out the ends at the motor side bracket that's all... took me two days to figure all this out as it was my first real mod... but it's not really all that hard and I would do it again in a heartbeat

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