BigS1975

I installed a Gm LS1 hot cam kit in a buddies 01TA had the PCM sent to PCM Performance for a retune.Got it back and the car runs good but at initial start up it still has trouble staying running for the first few seconds.It was stalling out at idle before the retune.I drilled the hole in the TB 2 sizes bigger than stock and stopped there before going any bigger and getting some of ya'lls advise.The specs on the car are:01 T\A 5.7 LS1,long tube pacesetters.3in Borla exhaust from headers back,Granitelli MAF,Hot cam 271int.dur.280exh.dur.,525 gross lift,hot cam springs and seats from SDPC.
Any help would be appreciated.