3.73's installed today, and...

Joel's98GT said:
RP oil has friction modifier already in it, i'm pretty sure redline does as well.

ok, I'll look into that, I'm gonna have to do it tomorrow when everything opens up after the holiday.

70w140 right? that seems to be the general "standard"
 
QUICK91LX said:
you definitely need friction modifier. ive never done gears myself in a car but i have changed rear diff fluid and i do friction modifier EVERY time

I'm actually gonna take it to Ford tomorrow, and have them replace the diff oil and add the friction stuff...

I'm HOPING that nothaving that is whats causing the whine, and that it's not that I have something set up wrong.