When did the GMC 420 4 speed transmission come out?

The SM-420 4-speed transmission was produced by General Motors between the years of 1947 & 1967. It was the standard transmission for GMC 2500, 3000, 3500 & 4000 series Trucks, & an option for 1000 &. 1500 series trucks.

When did the GM sm420 transmission come out?

The SM420 is an impressive, heavy-duty truck transmission designed for and used in ½, 3/4, 1 and 2 ton trucks. The SM420 was made by General Motors from 1947 to 1967.

What was the casting number for a GM 4 speed transmission?

The casting number was T10 plus two numerals, or “13-04.” GM muscle cars manufactured between 1963 and 1974 were frequently equipped with the Muncie M21 and M22 four-speeds. The case was made of aluminum, with a seven-bolt cover and 36-tooth synchro rings.

What was the first four speed manual transmission?

New Process four-speed manual transmissions came in three versions. The aluminum or iron-cased 440/MY6 helped power 1981 to 1987 trucks, and featured a non-synchronized first gear. The low-gear 435 was found on 1964 to 1972 vehicles. The casting numbers starting at C-9, followed by four digits.

The SM420 is an impressive, heavy-duty truck transmission designed for and used in ½, 3/4, 1 and 2 ton trucks. The SM420 was made by General Motors from 1947 to 1967.

Can a GM Muncie 420 be used with a Chevy bellhousing?

While the Muncie 420 can be used with any GM engine having the “regular” GM transmission bolt pattern, this transmission installs more easily with the open bottom Chevrolet bellhousings because the lower holes in the transmission case are threaded rather than drilled for clearance.

What kind of transmission does a GM truck use?

The SM420 is an impressive, heavy-duty truck transmission designed for and used in ½, 3/4, 1 and 2 ton trucks. The SM420 was made by General Motors from 1947 to 1967. Military specification versions were made through the early 1980s. The SM420 is found in GM trucks, busses, heavy equipment and various military applications.

What kind of transmission does a GM Muncie have?

GM Muncie SM420 Transmission The SM420 is an impressive, heavy-duty truck transmission designed for and used in ½, 3/4, 1 and 2 ton trucks. The SM420 was made by General Motors from 1947 to 1967.