SM465 swap into 92 suburban.

[PrairieDrifter]

I'm zero help, but I have a question you might be able to answer... On the SM465, especially with tall gearing, is it practical to use Low gear as 1st gear in normal/street driving? Or is the non-synchro that big of a deal? I've only driven two trucks with non-synchro low gear, and both were conventionally geared so Low gear was just for crawling around, basically, and both were 15-20 years ago and only ranch duty. I'm curious if a big tire/3.73 truck could use low as first gear, as "1st" would be pretty tall.

Like said above. 1st is fine to get going, but you won't be able to downshift easily or at all into first. 1st gear would be better with a big tire and higher ratio, that being said I doubt you would have to downshift into first for most turns.

I've thought about that theory as well. With a manual and big tires your power band should be pretty nice depending on ratio and tire size. Then you should get higher speed with lower rpm's, more of useable setup. Then you wonder if first gear would be useable or if you would have to use it or not, and if second would lug too hard for turns.

 

[Steelbuddha]

The granny low can be very handy leaving an uphill stop with a heavy load or a trailer. Getting it into first gear takes some finesse, though.

 

[Hunter79764]

I seem to remember double clutching (clutch cycle once to get out of first/second and into neutral, then a second time to get into 1st/Low) and that working well, but that was 99% on the older trans from the '48, and typically used when climbing up some steep stuff and about to stall out, so vehicle speed might end up being zero (or slightly negative) by the time the shift actually happens.
Like I said, I drive a stick daily, and I feel like I can count on one finger the number of times I need to put it into 1st while the vehicle is moving. As long as I don't have a special headache upshifting, I feel like this idea would work. Especially if paired with a torquey motor (which I plan on). Thanks.