Specifications

OPTION 1: These adapters work best for the 2WD TH350 transmis-
sion but can also be used with a 4WD transmission. This adapter
is 1.50” long and comes with a new 23 or 21 spline output shaft.
The transmission will need to be torn down to install this output
shaft. This kit comes with a new seal, gaskets, and hardware
for coupling the TH350 the New Process transfer case.
TH350 to New Process T/Cs
50-6802 Flush & long 23 spl. 1.5” long adapter kit
50-6801 Flush & long 21 spl. 1.5” long adapter kit
Optional Items:
716008 Trans mount (or) 716021 trans mount (or)
716017 Trans mount
OPTION 2: These adapters only fit the NP231 transfer case and the 4WD
TH350 transmission. This adapter is 1.50” long and comes with a new 27
spline New Process transfer case input gear. The transfer case will need to
be torn down to install this gear. This kit comes with a new seal, gaskets, and
hardware for coupling the TH350 the New Process transfer case.
TH350 to New Process T/Cs Optional Items:
50-6804 NP231 T/C up to 1994 27 spl. 1.5” long adapter kit 716008 Trans mount
50-6805 NP231 T/C 1995 & newer 27 spl. 1.5” long adapter kit 716021 Trans mount (or) 716017 trans mount
OPTION 3: These adapters are 3.65” long and are designed for the short 4WD output shaft. If you obtain a 2WD transmission
then you would be required to install a new rear output shaft. We offer a kit that will supply you a new TH350 4WD output shaft. If
you obtain the 4WD transmission, select the kit that excludes the output shaft. The kits use a spud shaft either 23 or 21 spline that
is pressed on to a roller bearing and then pressed into the adapter housing.
2WD TH350 to New Process T/Cs (with output shaft) Optional Items:
50-6300 Flush 23 spl. adapter kit 716008 Trans mount (or)
50-6307 Long 23 spl. adapter kit 716021 Trans mount (or)
50-6301 Flush 21 spl. adapter kit 716017 Trans mount
50-6305 Long 21 spl. adapter kit
4WD TH350 to New Process T/Cs (less output shaft)
50-6304 Flush 23 spl. adapter kit
50-6308 Long 23 spl. adapter kit
50-6302 Flush 21 spl. adapter kit
50-6306 Long 21 spl. adapter kit
700R: This is the first automatic overdrive that GM
produced. Introduced in 1982, this transmission was
offered in two different bellhousing / case designs (60
& 90 degree bolt patterns). The internal components
of these 700Rs can be interchanged if necessary.
When this transmission was first introduced, it quickly
developed a bad reputation for certain weaknesses. In 1987,
GM resolved all of the problems that previously existed. In the
1990s, the name of the 700R transmission changed to 4L60. These
transmissions are ideal for many conversions because of the 30% overdrive.
The overall length of this transmission is 23-3/8”. It has a 1st gear ratio of 3.06:1;
2nd 1.62:1, and a 3rd gear ratio of 1:1. When converting using this transmission,
we recommend that you cut the two tabs as illustrated in the TH350 section. This will allow for exhaust and firewall clearance. (Note:
We offer a 700R lockup bypass kit, P/N 24-700R). We offer a couple of adapter options when using this transmission, depending
on which transmission you get (2WD or 4WD). The first kits listed will work on either a 2WD or 4WD transmission and will require
the output shaft to be replaced. These kits have a 700R output shaft with either 21 or 23 spline and uses a 1.50” adapter housing.
The other kits we offer only fit the 4WD transmission and only the NP231 transfer case. These kits come with a new 27 spline input
gear to fit the stock 700R 4WD output shaft and the adapter is 2.50” long.
700R to New Process T/Cs Optional Items:
50-9102 1.50” 2WD or 4WD 700R to 23 spline New Precess transfer case kit 716008 Trans mount
50-9103 1.50” 2WD or 4WD 700R to 21 spline New Precess transfer case kit
4WD 700R to New Process 231 T/Cs Only Optional Items:
50-9104 2.50” 4WD 700R to 1994 & earlier New Precess 231 T/C kit 716654 Trans mount (or)
50-9105 2.50” 4WD 700R to 1995 & later New Precess 231 T/C kit 716055 Trans mount
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transmission to t/c adapters (1987 & newer)