"Big Dooley" it was called back then....
the transmission, has a side plate that tells ALL.
look there, (will need serious cleaning from 1983 to now)
GM matches, tranny to engine power and torque max.
they have M/T and A/T tranny. 4speed Muncie, (my first love) m20
M40 Th400 3speed slush pump?
here is first google hit on spec;s like a answer on other post. same'
note 2 , 454s one with TBI
The one-ton model designation was the C or K 30 for GMC and 3500 for Chevrolet.
(wiki quote, sure read the wiki on you truck first)
there is no lack of information on this truck
use GOOGLE it really is your friend.
here is a search.
here is K30 (which is it C or K?) learn this first
= 2 Wheel Drive (1960-2002)
= 4 Wheel Drive (1960-2000)
there is how you can research your car, then ask more detailed questions, (peel the onion)????