I would get rid of that transmission and look for a S-10 T-5 transmission with .72 overdrive. Pretty easy swap. The 92 and earlier transmissions have the same mount pattern as the early muncie 318. There is no shift linkage cause its inside the trans. You will have to shorten your driveshaft as they are about 3 inches longer. There are two types , World class and Non World class. I'm putting a 92 Non World Class in my 56 3100 currently.
