89 F150 trans lube?

[fitzwell]

Just got this thing & want to service the box. 89 F150, 300 six & 5spd manual (MR5R2). Anyone have an idea on trans lube?? I've heard Mercon, MerconV, Syncromax, Bud light..... Anyone here have a recommendation?

[2011GT]

Mercon V

[thesource]

ATF in general is all you need. You can even run a 10-30 motor oil in it.

[JC316]

I ran syncromesh in my M5R2 for the scratchy syncros. Seemed to work well.