any have a guestamate on around what ill run in the 1/4 in an auto 03 GT with 3.73's and a predator tuner?

 

Expect low 14's. You really chose a poor gear for an automatic, especially if it's staying NA. Ideally you'd need atleast 4.10's and even 4.30's to make up for some of the extra parasitic loss the automatic suffers.

It'll be capable of a high 13 with those mods. The tuner won't really do squat for you HP wise other than adjusting the timing.