[Randy's R&P]

So if I'm reading that right, I'm fine for putting aftermarket 5.29 gears into an '87 thirdmember using the YK Y8-A install kit that has the fat inner bearing because according to Drew's post "'79-'85 rigs have SPH gears and a "thick" inner pinion bearing designed for the 4cyl housing. All aftermarket "4cyl" R&P and inner pinion bearings are identical to these factory parts, that way the same part numbers will fit all '79-'95 four-cylinder rigs.

I guess the YK T8-B is for rebuilding using factory LPH gears on the 86-95 thrids? Is this correct or did I fawk up the reading of this?

You're correct. The -B kit is only for the '86 and up OEM pinions. If you have 5.29's, the -A kit is what you need.