Turbo 5.3 Silverado

[Shortyno10]

Might not be the right thread, but the setup is a forged 5.3, arp studs, tbss intake, Holley 92mm tb, Texas-speed cam 224/228 600/600 114lsa, vs racing 78/75 billet turbo with Huron speed kit and 80# injectors, 3.42 gears, 4l80 with a 1600-1800 stall converter. My problem is it won?t make any boost till about 3500rpms then it takes off like a bat outta hell. I have boost leak tested and it held 20lbs no problem. Could it be the converter? If feels really tight like it?s almost locked and is a complete dog out of the hole. Best can describe it. Any help is greatly appreciated thanks

[cobaltssoverbooster]

if your converter stalls before you move enough air to make the turbing housing AR efficient then your not going to spool. Depending on the AR for that 78/75 you might not move enough air with the 5.3 to get it going in that lower rpm range. technically you dont want to build a pile of boost prior to 2800 because you can twist the hell out of the crank and load the bottom end into an undesired state.
before we go blaming any parts though, lets see what your tune file and logs have to say. Go into advanced post and add them in for us to look at.