Truck in question is a 66 Camper Special with the "close ratio" NP 435. Thinking about swapping it out with another that has the super low first gear. I know if I go this route and find one newer than 1967 it will have the 23 spline input shaft and will necessitate a new clutch disc. But
Please explain to me how u swap input shafts without swapping countershafts too? Being that the 2 gears are different diameters and tooth profiles, how would they mate to the same countershaft gear?