transmission problems 01 silverado

[philds19]

ok i have a tuner here in NC great guy i've known him for years and he can tune the hell out of gm's well i finnally got my ls1 in and got it tuned made 410whp and 371torque. well after i got it on the road (days later) because of rain. when i get on it BANG BANG BANG it smacks the rev limiter before it finally shifts after i let off the gas pretty much. well i have 24's on it at the time and been have touble with them leaking air so i've put the stockers back on. so i get him to fix the shifting problem it does great and pulls like a champ. but i noticed right before pulling back in the shop when i would barely give it gas to accelerate it wouldn't shift out of first til like 3500rpms at like 5% throttle. (i didn't really say anything then wasn't sure if it was my converter since i've never had one before 2500stall) well after we tested it i got him to change my tire size for the stock rims. well i go home change my wheels and it still banging the rev limiter. and still not shifting out of first till the rpms are abnormally high. well i took it back and he changed it(didn't do anything) he says he changes it to shift out of first gear at 9mph and shift at WOT at 30 (well below the 6600rpm rev limiter) but it still doesn't shift til 19-20mph and this is less than 5% throttle. and it still hitting the rev limiter when i get on it. he said that the tranny was goin out slipping or something, but it doesn't feel like its slipping. DOEZ ANYONE KNOW WHAT THIS IS. i didn't know if it was my first gear solenoid or what,, it seems like the tranny isn't recognizing the changes though.

any help would be appreciated thanks

[tech946]

cant help but where in NC are you located, i live in apex just out side Raleigh

[philds19]

i'm in east durham right outside of raleigh.