David compares the differences between a 4L60E and a 700R4 Transmission.
From a visual standpoint, the 700R4 has a case connector on the driver side of the unit for lockup along with a governor cover. These units feature a hookup to a TV cable on the passenger side, which controls the transmission. 700R4 transmissions were produced from 1982-1993. Early 700R4 transmissions had mechanical speedometer gears versus the later VSS. Between 1982 and 1985, the 700R4 had a 27 spline input shaft. From 1986-1993 this was replaced by a 30 spline input shaft.
A 4L60E has a case connector on the passenger side of the vehicle where the wiring harness will hookup. This connector is located next to the servo cover. As opposed to the 700R4, there is no governor cover. The 4L60E 1 piece case was produced between 1993 and 1996. These units were the same shape as the 700R4 but were controlled by a computer. The 1 piece case and 700R4 both feature a 4 bolt pattern on the rear.
From the year 1997 and up, 4L60E transmissions had a 2 piece case with a removable bellhousing and a 6 bolt pattern on the rear. Starting in 1999, LS engines had a 4L65E, indicated by having a top bolt hole at the 12 o'clock position. Units produced in 2007 and later are 4L70E's indicated by a 15 pin connector versus the old 13 pin connector.
The transmissions produced in 1993 and 1994 are interchangeable for any 4L60E 1 pc cases. 1995 transmissions, however, are vehicle specific because the OHMs have different readings.