I would recommend the Dana 60 solution. You should be able to reuse your 35 spline axles and brakes. Truck Dana housings are easy to find for less than $200.00. Make sure the side carrier bearing has not spun in the housing to avoid additional machining costs (common problem, easily fixed). You will need to buy a new spool, bearings, seals, gears, companion flange, housing ends, ladder bar mounts, and shorten the driveshaft, but altogether (with your existing axles and brakes) you should be able to permanently solve your rear end troubles for less than $1,000.00. Check with Dr. Diff on prices. And you could sell the 8&3/4 carrier and spool to make up for a lot of the difference. And once you have a bullet-proof rear end, you can almost forget about the major reason that 727s explode.