ShadowDrake

What exactly is "ect" in your mods? None of the things you listed should have had an impact on the tune. In fact, it should be running just fine. If it's not, a tune is NOT going to fix that. You may be able to patch over the problem (probably a vacuum leak) with a tune but you're still going to have many inherent issues.

Get it running right first! Also, "running like crap" isn't enough of a description. What exactly is it doing?

1999 GT

^^ its not so much that the car has a problem, it just isnt running to its full potential with the mods i have done. for example my buddy has an 03 gt with the same mods along with a dyno tune, minus long tubes and he still gets me by about a car to a car 1/2...and yes i have the driver mod...but regardless, i made an appointment to get a dyno tune next week. so that will burry the hatchet. i will keep everyone updated with numbers and vids.

ShadowDrake

Well the LTs would be the only thing that might cause an issue but it would just be a driveability issue, not a power issue. The front O2s being farther from the exhaust valve would cause the ECU to overshoot 14.7 AFR and cause some problems with light throttle - but those O2 sensors aren't used at WOT. He could have extra power from spark advance and adjustment of AFR. I don't think it's so much that you have something wrong, just untapped potential.

1999 GT

yea exactly...so we will see what happens once i get the tune