'91 caprice classic tranny

My car has a LO3(305), but not to sure about the tranny, I was told 700R4, 4L60,and 4L60E! Which one is it,cause its burned up and would like to rebuilt it to save sum money.

Welcome to AF!

The transmission WON'T be a 4L60E - that's an electronic controlled transmission that first saw use in the Caprice in 1994 ('93 in other carlines).

The 700R4 and 4L60 are for all intents and purposes, the same unit, although I refer to a particular trans as a 4L60 if it has an auxiliary valve body and a 700R4 if it does not. All made between 1987 and 1993 fit into this category (4L60) while 1986 and earlier are pure 700R4s.

You cant go wrong w/ a Dealership right? I gave them my last eight they told me 700R4 is what camn in it(everything is still OEM). A local transmission shop here in my home town looked @ it and told me 4L60. Is the dealership wrong?

My '91 has a factory 700R4. 4L60's came later.

A "4L60" is a redesignation of the TH700R4. It is said to be easier to determine what it is to be used in with the 'new' designations. The way this works out is:

First digit is number of forward speeds
Second digit is design - L for Longitudinal mount (front engine rear drive) and T is for Transverse mount (front engine front drive or mid engine rear drive [Fiero]).
Third and fourth digits are the weight capacity (60 is 6,000 lbs GVW etc).

So, in 1987 (yes this happened in 1987 - look it up), GM redesignated their transmissions. The transmissions that didn't get a redesignation are the TH200C and 4R models.

TH400 became 3L80. TH700R4 became 4L60. TH125C became 3T40.

Much of the paperwork on the cars continued to call the TH700R4/4L60 a TH700R4 into the 90s, but the fact is the official redesignation took place for the 1987 model year.

TH700R4 and 4L60 are interchangeable terms beginning with the 1987 model year.