After hastily spending $250. On a wide track front dana 30 so we could obtain the 56" track we still were not sure what to do with the rear. As I stated before an offset differential amc 20 was never produced in wide track, only a centered differential version was made after quadra trac was discontinued in 1979. So after some very precise measuring it was determined dana 44's from a quadra trac equipped Wagoneer could be used by shortening only one side of each housing. This could only have worked out better if we would not have bought the dana 30 front. Needless to say we lost are asses on that purchase. So here is how it all went together. Front axle from 1979 quadra trac Wagoneer, shorten driverside by 4" and move spring perch in to give 27 1/4" spring center to center, (which is stock CJ). This will give you a track of 56", equal to stock CJ wide track. The original long driverside axle shaft can also be cut down and resplined, no need to have a custom axle made. The passengerside spring perch is cast into the housing and cannot be moved, but just happens to be in the right spot, and since we switched to Wrangler front springs they are the same width as Wagoneer. Otherwise the spring perches on a dana 30 wide track are too narrow. This will also align the pinion angle up correctly. And remember that the shackle reversal kit moved the axle ahead 1 1/2", so if you stuck with a dana 30 you would have to lengthen the front driveshaft 1 1/2", BUT and this is the neat part, a dana 44 differential housing is 1 1/2" longer, OH YEH, a stock front driveshaft bolts right up, no lengthening. Use the Wagoneer spring u bolt plates and relocate the driverside shock mount to match the passengerside. Upper wide track bolt on shock mounts will have to replace the welded on narrow track shock mounts.
Okay, rear dana 44 from 1979 quadra trac Wagoneer. Shorten the driverside by 2 3/4" and relocate the spring perches to the bottom. Again the stock axle can be shortened and resplined. The differential center line will still be off center by 1 1/2" from the transfercase but if you use a double carden driveshaft it will eliminate any vibration. The alternative to this was to shorten the passengerside by 1 1/2" and the driverside by 1 1/4" but then you would have to get custom axle shafts made for both sides. It worked out cheaper to have a double carden driveshaft made. The rear spring u bolt plates are stock CJ with the shock mounts with the u bolt holes elongated with a milling machine tc accommodate the bigger diameter axle.
So there you go strong dana 44's front and rear to handle all the torque from that 401. We stayed with the 6 bolt lug pattern because we had factory chrome wagon wheels and is a stronger set-up. This also gives you G.M. type front disc brake calipers which I prefer over the CJ type, a little easier to change pads. Keen eyes will see no rear brakes, you can stick with the drums or go with rear disc brakes like we are.