Specifications

TRANSMISSION TYPES & TRANSFER CASE ADAPTERS
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transmission types & t/c adapters (1980-86)
When considering an aftermarket transmission, it is important to determine what type of transmission you will require for your driving
habits. The three transmission types listed in this section will help you to determine the type of transmission best suited for your
particular style of driving.
CAR-TYPE TRANSMISSIONS:
Muncie (Car) 4 speed (M21/M22): Used in cars 1964 to 1974, this aluminum case transmission measures 10-1/2” long. The
1st gear ratio is 2.20:1; 2nd 1.64:1; 3rd 1.27:1, and a 4th gear ratio of 1:1. This is an externally shifted transmission and any adapters
using this transmission will require shifter components. We offer an adapter kit that includes a new main shaft, a 5” aluminum
housing and the necessary seals and hardware. When ordering this kit you will also need to consider a Hurst shifter, shifter bracket,
and shifter rod kit. We also now offer new transmissions withthe adapter kit installed, call for pricing.
Muncie M21/M22 to Dana 300 Optional Items:
50-6000 5” 23 spline adapter kit 715600 Hurst shifter 715625 Rod kit male studs
715501 Shifter bracket 715626 Rod kit female studs
716021 Trans mount (or) 716017 Trans mount
Borg Warner Super T10: This transmission was produced in 4 different versions. There was a Borg Warner T10, a Super T10
(thin hub), a Super T10 (thick hub), and a Super T10 (2nd design). We only offer kits for the Super T10 thin hub, thick hub & 2nd design.
Before you purchase an adapter, you should identify which transmission you have. The case length is 10” long and the most common
gear ratio is 2.64:1 1st ; 2nd 1.75:1; 3rd 1.33:1; and 4th of a 1:1. This transmission is side-shifted and will require a shift bracket
and shift rods. We offer an adapter kit that includes a new main shaft and two aluminum adapter housings that add up to 7.625”,
plus the necessary seals and hardware. When ordering this kit you will also need to consider a Hurst shifter, shifter bracket, and
shifter rod kit.
B/W T10 to Dana 300 Optional Items:
50-0701 7.625” 23 spl. Super T10 adapter kit (thin hub) 715600 Hurst shifter
50-0801 7.625” 23 spl. Super T10 adapter kit (thick hub) 715502-NS Shifter bracket
50-0901 7.625” 23 spl. Super T10 adapter kit (fine spline rev.) 715627-NS Rod kit Super T10
716017 Trans mount
TRUCK-TYPE TRANSMISSIONS:
SM420 Truck 4SP: This transmission works great in Jeeps. The
overall length is 10-1/2”. It has the lowest 1st gear available of 7.05:1;
2nd 3.57:1; 3rd 1.7:1, and a 4th gear ratio of 1:1. This transmission was
used in GM trucks from 1947 to 1968, and has
a 10 spline output shaft. As the years
progress, it is getting harder to find this
transmission and parts. The kit we offer is
5.25” long and has a new spud shaft that
couples to the Dana 300 transfer case.
This kit is supplied with the proper gaskets
and bolting hardware.
SM420 to Dana 300
50-9702 5.25” spud shaft 23 spl. adapter kit
Optional Items:
716021 Trans mount
SM465 Truck 4SP: Used from 1968 to 1988, this transmission replaced the SM420. It has an overall length of 12”. The 1st gear
ratio is 6.58:1; 2nd 3.58:1; 3rd 1.57:1, and 4th gear ratio of 1:1. This transmission was used in both the 2WD & 4WD vehicles.
Throughout its 20 years, the transmission case never changed; however, we have seen three different output shafts. The 1968-
79 4WD transmission used a 10 spline output shaft, which is easily adapted to. The 1968-88 2WD version used a 35 spline output
shaft. This transmission can also be used, but not without output shaft modifications. The 1980-88 4WD tranny used a long 32