I would like to ask for input on the options that are available when replacing an SM420 and maintaining the strength and durability if not exceeding it while increasing highway speeds at a suitable RPM.
At this point Differential Gearing is not an option that I am ready to explore.
The first thing on my list is purchasing a Gear Vendor Overdrive unit. Although I would like to explore the options of a newer 5 or maybe even 6 speed Manual Transmission?
Right now I have a Small Block Chevrolet (SBC) mated to the original SM420 in a 1955 2 ton truck. I am working towards building a truck that will do long highway runs with a goose neck hauler (Even if it happens to be at a slower pace than the heavy haulers that are coming out now 60 years later.
I did find a bit of information regarding someone installing an Eaton 5 speed transmission behind a SBC which came out of a 1984 chevrolet C something or other.
Anyone familiar with any model of old truck I should be searching out/researching for a good manual transmission to snag as an alternative to the Gear Vendor Overdrive unit?
Thank you !
Last edited by Noonan; 09/02/2019 4:20 AM.
