5.0 70 or 75mm throttle body?
 

looking to upgrade my stock tb for something bigger and better but dont want to go too big if i'm going to end up losing power. my car is pretty much stock right now besides c.a.i. and long tube headers w/ OR h pipe. just want to know if i should get the 75mm or will it be too much right now???

Go with the 70 for now, unless you plan on some major modification in the near future. A 70 works really well with a n/a stang, even with a bunch of mods. A 75-80 is usually better suited for forced-induction.

Unless you plan on cuin change with H/C/I etc then just get a 65mm itll keep the intake air velocity up while allowing more air than the stock unit.

75 if you have an aftermarket intake that has an opening large enough if not do at least 70

Dont get the female syndome lol! bigger isnt always better just cause the hole is bigger dosent mean you need to match it!

but hey opinions are like assholes!!

In 5.0L Ford Dyno Tests by Richard Holdener, he extensively tested many typical 5.0L modifications, and for most 5.0's, even with numerous modifications, the 65mm TB made the most power. Stroked and/or blown engines respond well to a larger throttle body, but otherwise, bigger is probably not better.

Would a 89 Fox Body Throttle body be compatible with a 96 GT (Stock)?

No they are completely different...96 is the 4.6

Thats what I thought... I appreciate the confirmation :)