i personnally would drop the pan and check the adjustment on the 2nd gear band, and add an upgraded 2nd gear band strut. the stocker is pretty weak and will flex under harder shifts and more power. of course there could be an internal problem. i lost 2nd gear on my stocker back in 00 bc of a torn front lip seal, that was shortly after i installed an aftermarket vb to increase line pressures slightly. the increased pressure i guess tore the stock seal. i would highly recommend picking 1 vender and buy all components from them. that way there is no question about all of the parts in an auto are working in harmony. that is the only way to keep an auto functioning the way it should. i have talked to guys that have mixed and matched parts and they have had nothign but problems, each component is designed and setup around the builders idea, you get to many different "ideas" in a system and you will have problems. may also try a pressure test to see how much internal leakage you have. do you research, ride in some trucks with different trans then pick the company you want to go with. that is what i did and i couldnt be happier, dont listen to someone that is just trying to make a sale!