You should be alright, as long as the rear is higher than the front.
$160 isn't too bad, when you factor in the facts of the time and $ spent on new ujoints, installing them, etc. In some cases the d/s yoke is messed up like mine, and causes that tranny seal to go out.
In your case I am sure you will be fine, I just suggested it because in the long run it will save you $, and time.
-86 ssp coupe
-66 mustang coupe...5.0, custom comp cam roller, Eddy perf heads, Pete Jackson noisy gear drive,holley 670 carb, airgap intake,t5 trans, 96 explorer 8.8 rear 373 gears,2005 gt brakes, full suspension roller mods
-01 bullitt true blue