5spd oil change questions ('91 2wd D21 SE)

[UFS207]

I got a '91 2wd Hardbody SE (V6/5spd) I need to do a transmission oil change on. Does the TSB about overfilling the oil by a couple pints on 4x4 V6 models apply to me? As far as I can tell the 2wd V6 equipped hardbodies have the same transmission as the V6 4x4's (FS5R30A), correct?

Also, had a really hard time finding GL-4 rated oil locally. I bought some Royal Purple 75-90W GL-5 stuff that specifically states on the label that it's safe to use in transmissions with yellow metals. Is it OK to use it?

Any help appreciated, thanks!

[Rev_D21]

No GL5 products should be used. Redline Oils makes a GL4 that will work. It won't hurt to overfill a little bit. But yeh even if the oil says it's safe for yellow metals it is not, GL4 only!!

[UFS207]

Does the TSB apply to the 2wd V6's 5spd though? I can't find a straight answer on the web. Guess I'll just measure what comes out and put the same amount (plus a 1/4 quart or so) back in.

Noted on the GL4 only. Can I use this GL5 stuff in the diff?

[Rev_D21]

I always overfill mine slightly, just a habit. It won't hurt them any. And yes GL5 in the rear diff.