i have a 2000 chevy 1500, it had a 5.3l vortec. i put a 6.0l vortec in it. and it starts and idols fine. when you go to drive it and start driving it, it is okay for a little bit but then it bogs out and doesnt get over 10-15mph. now it still has the computer from the 5.3l in it. but there is many things this could be. and it hard to find this out. the service engine light is also on, can anyone help me?

 

maybe if you were to get a computer from the original vehicle it might work or else try a superchip programer that would delete the existing 5.3 settings and store them on the programer and then download 6.0 settings,i think you have to get flashpaq for 6.0. it could be fuel rail set up or electronic settings

 

sounds like its electronic settings in original computer, some guys are getting just a computer for engine but it could be something simple as getting a superchip and reprograming

 

Just got finished putting in a cam on my 09 6.2 and had to spend many hours tuning to get it right (firming up shifts setting idle at under 5mph, setting new max rpm's for each gear etc) ----- just using a programmer will not work for everything related to the engine and tramsmission.