I was wandering about it. I've only heard of very few. I bought a 1986 chevy 4wd short bed a few weeks ago. It has the 4 speed overdrive trans with the flat bar shifter like old hurst shifter. The label with RPO codes in glove box shows MM7 ( 4-speed man trans ). I was interested if anyone had any other information on it.
one of my other trucks that I've had for about 7 years is 1987 chevy short bed 4wd with granny gear 4 speed and has the normal round bar curved shifter.
Nice I see yours is a K1500 4x4 too. These did not come behind 350's at all. 4.3, Wee O Fives, and 6.2 Diesels Only. There is 2 different RPO codes. MM7 in the 4x4,'s and MY6 for the 2 wheel drive models. It's been said that the Cast Iron models in the 4x4's are best and stronger than the 2wd Aluminum units, but the other guy doing a build here, has a cast iron unit and it's a 2wd, so apparently, there are some Cast Iron 2wd units that I've been told didn't and don't exist. So it could be that MY6 is the Aluminum model and MM7 is the cast iron model.
As far as gear ratio's, if you look those up, this trans is ALMOST identical to a 700r4 gear ratios. Off by like .0X in any gear. Some will complain about the wide ratio on this trans, but if you compare it to the SM465, the other trans you're speaking of with the granny 1st, the ratio's are no more wider than that trans with exception this one has OD instead of a Granny Low. The SM465 is a stronger transmission, but the A833 comes with a stronger clutch for some reason. The clutch disk is an inch bigger. According to everything I've found on these things, they're pretty damn strong and under rated. If you decide you don't like it, I know there are several members on this forum that will be happy as hell to take it off your hands, BUT, I think it would be a crime if your truck is original with it, and you have the RPO code on the SPID label, to swap it out of the truck. I'd keep that truck as original as possible. Even if you get a new motor, like a 350 crate, I think I'd hold onto that Wee O Five out in the tool shed or covered up. Or rebuild the Wee O Five. It's just a very rare option, so to some of us, it's worthy more than others.