I am upgrading my truck and want to know if I will have to have  someone custom tune my vehicle or will it run fine without doing any tuning.her is what I have and am doing to it-98 GMC sonoma with the 4.3 V6 w/vortech heads-7.625 rearend,4L60E trans--I am putting in an electric fan,throttlebody spacer,Already has a CAI,cat back single exhaust,positraction differential.Also thinking of headers.I am leaving the engine stock.Slight possibility of having the heads mildly ported and polished way down the road.I,ve never done these types of upgrades before especially a truck with a computer.Any and all help is appreciated.  

yeah you should do some ecm tuning....i would talk to JET or hypertech.....headers and a cam would wake it up  

Cool.Thanks for the info.  

Best thign to wake up that 4.3 is a cam upgrade with a computer tune.