78-79 Bronco/F150 are 31 spline not 28 so, that wasn't what you had in there (they would have been tapered roller bearing as well).....maybe F100.
As for having to buy a new locker, you really don't have to.....when I converted my early Bronco to 31 spline, I just replaced the side gears (drivers) with 31 spline versions and was good to go.....I only paid around $50 or so for the parts (back in '98)...they're quite a bit more now but, still a hell of a lot cheaper than replacing the whole unit.
Sorry maybe you missed the 1st part of the Thread That was Currie's price 120.00 cut and respline per my phone conversation with a sales person I won't mention to avoid any repercussions on him! And as for the 28 31 splined Fords they did a lot of weird shit just look at their front ends F150 Supercabs had leaf fronts but not regular cab. 3 different front axle strengths available 289 with five hole and 6 hole bell housings. Torinos with 28 splined big blocks on and on and on.
With the Bronco/F150 tapered roller bearings you have the added benefit of them being bathed in the rear end's gear oil making them virtually maintenance free...other than normal oil changes.
So, if you're paying to have the shafts shortened, spend the extra $150 or so (price of the drivers last I checked) and enjoy a big upgrade in strength, (those bearings will last a lot longer) and peace of mind.....just my opinion though
And $125 a piece for cut and respline is too expensive, Currie will do it for $85 IIRC
Hans