[js1989]

hi

what it's the best on my mustang 1989

3.55 or 3.73 ???

thank

 

[dollarbill]

What kind of mods do you have or plan to have? If your plans include mods to raise the power band, get the 3.73s. If your mostly stock I would get 3.55s. You will get lots of mixed responses to this but the fact is a stock 5.0 falls off over 5k rpm, so the 3.55s will keep it in its powerband a little longer. You should find the debate thread and read it.

 

[speedytang]

You did not say what transmission so here is the break down.
AOD- NA 4.10
AOD-Supercharged 3.73
5speed-3.73
5speed- Supercharger 3.55