Manual transmission from 1990 K5

[Frederick M. Wiley]

Have a question about this transmission is it a 4 speed or 5 speed and can it be fitted into a 1975 K 5 I understand I have to replace the shafts but it there any other problems that I will run into?

 

[nvrenuf]

The '90 should have an sm465 granny 4spd (no 5 spd's offered). It's common for square body trucks but '85+ are desirable because of the hydraulic clutch set up. If you want to use the hydraulic set up you'll need the bellhousing and pedal assembly. If you don't want to swap pedals an '84 & older sm465 mechanical linkage bellhousing will fit fine.

The real trick is the '85+ transmissions have a long 32 spline tailshaft whereas your '75 should be a short 10 spline. You'd need to either swap the tailshafts to use your transfer case or use the transfer case (and adapter) from the '90 Blazer (however this will require significant driveshaft mods).

 

[Frederick M. Wiley]

Thank you for this information, I do have the bell housing and hydraulic assembly with the pedals stripped from a 1990 k5, also kept the firewall plate that assembles it, I was lucky to find this 1975 K5 trim Cheyenne which in Hawaii is very rare, but had been stolen with the loss of the engine and some front parts, the body on this one had hardly any rust on this 43 year old usually when I open the door it just falls off on similar 1975s

 

[RootBreaker]

I took all the hydro stuff from a 1990 k5 blazer including bell housing and stuffed it into my 1982 c10 diesel cab and to my 1991 caprice police motor stuffed between the 1978 k20 camper special frame.. so anything is possible.. LOL