I have the vortec max with 2300 magna charger.8 psi shiting at 6300 with ls9 cam.rite now i have my torque converter locking up in 4th gear at 45mph,i did some reading would i benefit from it locking up in 3rd gear?if so what rpm?my truck goes real good looking for any improvements.am i shifting my truck tp early?i have ls9 cam ls7 lifters changed springs but not to the doubles>>

 

I would say no and It's not wise to lockup the stock converter at wot with that much power. They were never meant to be locked at wot with a supercharger.
Ask circle d and yank.

Sometimes if the truck doesn't have enough power the truck will actually slow down.
With ur type of supercharger it's not critical to load the engine like u would a turbocharged setup.
Some do lock it up and others don't. You'll get mixed opinions but I wouldnt. There's a reason why aftermarket companies make multi lock up clutch converters.