I have a built trans with 3.29 gear but have never changed the trans tune. The speedometer is correct, and listed as a 3.29 in the speedo tab, so I'm guessing the reluctor wheel was replaced when built. Had a 3200 stall convertor, but it was toasted so it was replaced with a stock GTP convertor. Not sure what the old one was, just know that it was smaller in diameter and blue. Not sure if the flywheel is stock, heard of people using a GT flywheel for some reason!?! The problem is a vibration under throttle, and it seems to lock up quickly and bog down mostly in 4th, also takes quite a bit of throttle to unlock. If I am passing a car and hit the gas it will stay locked unless I hit about 1/2 throttle then unlock. All suspension parts have been replaced on the front end to rule that out on the vibration. So my question is, I've heard of people using a stock GT tune when switching to 3.29 gear. Do you think this would help/hurt my problem, and which tabs do I need to change if this could fix my problem? Sorry for the long post, just want to get as much info out there as I can...