me i tell you it's me
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You would need to install a vacuum line to power the vaccum modulator on the older 350 turbo hydramatic trans....to allow it to shift. The tranny will already have this modulator installed on it (passenger side, front / middle of tranny). If the one that comes with yours is bad, you can get a new one for cheap at any auto parts store. I believe the tranny dimensions are actually the same, as far as length, and I'm positive it would bolt up to the block, since the 350 engine block has been the same for many many years. If you get a TH350 out of an 88-95 model, it will have the electronic speedometer hookup, which is necessary to tell the engine computer what speed the car is travelling. It will definitely work, the transmission mounts are the same. I would measure the length of your transmission first, and the length of the 700r4. Worst case scenario, you could get a driveshaft out a truck with the same wheelbase as yours that had the TH350 (they all bolt into the rear ends the same way). The difference is, you will have a 3 speed tranny instead of a 4 speed which you have now. I would not recommend this, unless you're aware of how much different the truck will drive (higher engine speed on the highway) and are ok with it. It would likely be cheaper and easier to get another 700r4, unless you are getting a screaming deal on the TH350. Many reputable transmission shops can rebuild a 700r4 for $1000 or less, with a warranty. Not sure if that fits your goals, just thought I'd add that. Or, a salvage yard is another option, but beware - there is no way to test a tranny while it's sitting in a junk yard, so you may get a bad one. A good avenue i've found is craigslist. You can just about find anything you're looking for, locally. Place an ad saying "wanted to buy: 700r4 transmission." Some gear head who is re-doing his truck will have one, and sell it much cheaper than you can get a rebuilt one for.