Just depends Al. Full widths run from as low as 63 to as high as 69 or 70. Yours would be a narrow full width, but close none the less.
On a budget you would want to look at a set of after market d60 housing ends and spindles, and then use all junk yeard 60 hubs and brakes.
But honestly, if you are looking for equal strength to the 14b, and want to shave as much weight as possible, a 40 spline semi float 9" will do everything you are looking for. That would leave you dollars left over to by a good center from tru hi. Strength wise, anything less then 5-600hp and 44-52" tires does not warrent going full float.
Select the housing of your choice, get a currie axle end and 40 spline shaft kit, get some junkyard 8.8 disks, then do the tru-hi center. Done deal. Going with a spool you will be under 3k start to finish. Detroit you are looking at maybe 3500.
Total weight on one of those with brakes is MAYBE 225lbs. Over 2 inches of ground clearence versus a stock 14b, and an inch over a shaved one.
My hi nine with a detroit has seen a few comps, and a lot abuse. With a 300hp stroker on 38 toyo's and only running 35 spline shafts my diff has been very reliable.
Tim (wicked yj) has been running a tru hi nine behind is high hp v8 for about 6 years now. Anyone that has known Tim over the years knows how hard he runs his stuff. He's using the Currie 35 spline set up.
There are a million ways to build a 9". But the center section is what will really determine how strong and reliable it will be.