Jet Power-Flo Throttle Body...it Worked for me!
 

I pulled the trigger on this one after a guy posted his youtube install and drive it on his new GM/Chevy full size (5.3l). Still skeptical clicking the order utton, but man; it is actually worth the money.

However, i cant really say fir sure if the Jet throttle body is better then oem or if I just needed a new OEM/Aftermarket throttle body. My truck was hesitating on cold starts when below 60F and shifting, when engine was cold, into 2nd was pretty rough, kinda jerked forward. That all disappeared with the new throttle body.

76101 JET Powr-Flo Throttle Body | Jet Performance Products Jet Performance Products

I also ordered the Mass Air FLow Sensor....but it came dirtier than my stock one (gonna give 'em a call)

Cheers!