Hello. I got the B2B back on the road Thursday after completing my 9 inch rear end swap. Details on how you could do the same swap follow for those that are interested:
First, I stumbled upon a 1970 Ford 1/2 ton truck at the boneyard. This rear end was a very good fit and requires no narrowing etc. The rear end has 3.70:1 gears and cost me a total of $85.00 dollars but I had to pull it myself.
Second, I took some measurerments. I measured the distance between the centers of the spring perches on the original rear end at 44 3/8". The Ford rear end needed to have the old perches and shock mounts removed and new perches welded on. I paid $17.00 dollars for new perches and $200.00 to a local street rod guy who did the precise measurements, welding and pickup and delivery. The pinion angle was 4 degrees.
Third, when I got the rear end back I thoroughly cleaned it and the primed and painted it up. The next day I yanked the original rear end. At the same time I removed the overload/helper springs and have noticed an improved ride since. I had to cut the original u-bolts and bought new shorter ones to compensate for the removal of the helper springs. The new u-bolts cost $30.00. At the end of the day the new rear end was mounted up. I used the original shocks that I had in the truck and they seem to be working fine.
Fourth, this is where I ran into a couple of problems. First, the Ford rear end had a different wheel bolt pattern than the Dodge. I hadn't thought about this because I thought Ford and Dodge shared the same 5 on 4 1/2 pattern but the Ford was 5 on 5 1/2. So I went to the boneyard and bought a pair of wheels with fair tires for $20.00.
The driveshaft required some modification also. I believe the distance of the new shaft needed to be 65 3/8". I took the original shaft to a local truck shop that put a new front-stub on it and possibly replaced the differential "yoke" as well to mate with the Ford pinion yoke. Cost $202.
Lastly, I had to hook up the brakes. I removed the factory hose to the rear brakes from the main line near the gas tank and bought an adapter to mate it to the Ford rear brake hose I bought. Cost for both about $30.00. I also had the drums turned $12.00 and painted them up. I then rebuilt the rear brakes, new shoes, hardware, and wheel cylinders- cost about $65.00. The Ford emergency brake is not hooked up but the cables are tucked up into the frame for now.
The new rearend works great! The brakes are dramatically improved, and the improved gearing helps out the cruising RPMs a little. I hope this is helpful to anyone considering this kind of swap and if you have any questions, need for part numbers, etc. email me at MBreva@Mninter.net. Jay

Jay,

What is the gear ratio of the new rear end, and how fast does the truck go now?