3/4 ton trans - The 1947 - Present Chevrolet & GMC Truck Message Board Network

michael bustamante · 12-21-2007, 12:40 PM

Does any body know what kind of transmission this is? I have a 4 speed manual trans from a 1960 Chevy 3/4 ton longbed truck. It has an E-brake drum set up on the output end of the trans and the E-brake handle is mounted alongside the shifter. It came with a 307 that was given to me mounted by the bell housing. Any info would be great so I can sell it. Thanks

60-66 Nut · 12-22-2007, 04:30 AM

If it's the original transmission out of a 1960, it would probably be the SM420 Muncie, which was built from 1947-1967. The SM465 did not come out until 1968. An easy way to tell is the shift pattern. If you pull the shift over toward you and back for reverse, it's an SM420. If you push it away from you to the right and back for reverse, then it's an SM465. Hope that helps.

60-66 Nut

michael bustamante · 12-22-2007, 06:42 AM

it does thanks. Now most muncies ive known had an aluminum case but this is cast iron and has a gm part # on it. I cant shift it rigth now because the shifter handle and plate are off. what do you think?

60-66 Nut · 12-22-2007, 07:50 AM

As far as I know, only the automotive style Muncie 4 speeds had the aluminum case. The SM420 and the SM465 truck transmissions are all cast iron. I think some if not all of the New Process NP435 4 speeds had an aluminum cover, but there were only a limited number of them used in GM trucks from 68-72. Another way to tell them apart is the PTO ports(cover with six bolts). The SM 420 has the PTO port on the driver's side, the NP435 has it on the passenger side and the SM465 has one on both sides.

60-66 Nut

Fred T · 12-23-2007, 08:42 PM

Here's a site with good general info on the 4 speeds.
http://www.novak-adapt.com/knowledge...on_gateway.htm

The 420 is one of the best 4 speeds for these trucks. Iron case and very durable. Compared to the 465 the 420 is small and light.

You might go to www.stovebolt.com if you want to post an ad. They have a good following for big trucks.

12-21-2007, 12:40 PM	#1
michael bustamante Registered User Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,841	3/4 ton trans Does any body know what kind of transmission this is? I have a 4 speed manual trans from a 1960 Chevy 3/4 ton longbed truck. It has an E-brake drum set up on the output end of the trans and the E-brake handle is mounted alongside the shifter. It came with a 307 that was given to me mounted by the bell housing. Any info would be great so I can sell it. Thanks __________________ 1967custom Last edited by michael bustamante; 12-21-2007 at 12:40 PM.

12-22-2007, 04:30 AM	#2
60-66 Nut Professional Beer Tester Join Date: Aug 2004 Location: Louisiana Posts: 453	Re: 3/4 ton trans If it's the original transmission out of a 1960, it would probably be the SM420 Muncie, which was built from 1947-1967. The SM465 did not come out until 1968. An easy way to tell is the shift pattern. If you pull the shift over toward you and back for reverse, it's an SM420. If you push it away from you to the right and back for reverse, then it's an SM465. Hope that helps. 60-66 Nut __________________ 60 Ford F100 Custom Cab 61 Apache Short Fleetside 64 C10 Short Stepside 65 C80 409 V8 5spd(X-Firetruck) 83 GMC 350 Olds Diesel 85 GMC Short Bed 86 GMC Short Bed 90 GMC R3500 Crew Cab 92 GMC 1500

12-22-2007, 06:42 AM	#3
michael bustamante Registered User Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,841	Re: 3/4 ton trans it does thanks. Now most muncies ive known had an aluminum case but this is cast iron and has a gm part # on it. I cant shift it rigth now because the shifter handle and plate are off. what do you think? __________________ 1967custom

12-22-2007, 07:50 AM	#4
60-66 Nut Professional Beer Tester Join Date: Aug 2004 Location: Louisiana Posts: 453	Re: 3/4 ton trans As far as I know, only the automotive style Muncie 4 speeds had the aluminum case. The SM420 and the SM465 truck transmissions are all cast iron. I think some if not all of the New Process NP435 4 speeds had an aluminum cover, but there were only a limited number of them used in GM trucks from 68-72. Another way to tell them apart is the PTO ports(cover with six bolts). The SM 420 has the PTO port on the driver's side, the NP435 has it on the passenger side and the SM465 has one on both sides. 60-66 Nut __________________ 60 Ford F100 Custom Cab 61 Apache Short Fleetside 64 C10 Short Stepside 65 C80 409 V8 5spd(X-Firetruck) 83 GMC 350 Olds Diesel 85 GMC Short Bed 86 GMC Short Bed 90 GMC R3500 Crew Cab 92 GMC 1500

12-23-2007, 08:42 PM	#5
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Re: 3/4 ton trans Here's a site with good general info on the 4 speeds. http://www.novak-adapt.com/knowledge...on_gateway.htm The 420 is one of the best 4 speeds for these trucks. Iron case and very durable. Compared to the 465 the 420 is small and light. You might go to www.stovebolt.com if you want to post an ad. They have a good following for big trucks. __________________ Fred There is no such thing as too much cam...just not enough engine.



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