1991GMC1500

I have a 1991 GMC 1500 I was also on craigsllist because I need a trans for it well I spoke to a guy that has the 700r4 That I need but it came out of a 2007 Escalade will it FIT in my truck the escalade is Also AWD I have RWD will I have to take the Transfercase off and switch tail shafts from mine too the 07 trans ? IF it fits ?

Chevy lover for life

No it will not fit.

The transmission in your truck presently should be a 700R4 or a old version of the 4L60E

Which basically the 700R4 was nothing more then a TH 400 which was converted to a 3 speed with over drive transmission.

The 4L60E was basically the same transmission - only a newer version that first appeared in the heavier trucks and then were put into the 99 and newer pick up trucks. The design was changed around about 2003 - because they had so many problems with the 4L60E - even when it was in the design stage - that they knew that they were going to have to make it bigger and heavier.

The 4L65E was the result and it is about 3 inches longer then the 4L60E

The wiring from one year to the next does not even interchange and the result was that there was a bunch of transmissions made - that none of them interchange. The 2002 is all by itself, as is the 2003 - 2004, and then it was changed once again for the 2005..

There is nothing to say that you couldn't spend more then what the truck is worth to adapt it to work in your truck, but you would need the transfer case, driveshafts, shift module, wiring harness, and all the other stuff to make it work.

Even at that, I don't know that the engine will bolt up to the transmission or that the torque converter would bolt up to the flex plate.

The days of taking a transmission out of a car, tearing it all apart, changing out the output shaft and bolting it up to a transfer case with the adapter off the old transmission is over.

Now unless you have all your ducks in a row, you can't even get a transmission two years newer or older to work in the same vehicle.