Currently I have a SM420 Muncie 4-speed, and I was wondering if the SM465 has higher gears than the SM420. I assume that both have a 1:1 in 4th gear? Is there another good heavy-duty truck tranny I can swap in to get higher gears? Any 5-speeds? Thanks for any help.


'48 Chevy 2 ton Flatbed
(daily driver)
'70 BMW 2002
My truck is older than my parents!