cornelius1988

What should I use in my 1988 5.0 lx

TrimDrip

Valvoline makes a synthetic oil that can be bought at part stores. 75w90 will do fine.

Tony71502

I use Lucas 80w-90 plus friction modifier.

mjr46

75w/90 will be fine if you use the conventional, you'll need to add 4 oz of friction modifier if you get the valvoline synthetic iirc it has it all in one

mustangGT86_05

Yeah you'll be fine with valvoline, and autozone can give you the recommended spec. I opted to not use synthetic though because it is more slick and I have heard its not as healthy for the trac lock clutches. Just make sure if you don't buy valvoline that what you get either has friction modifier in it or you add some in, you'll mess up your trac lock quick if you don't.