I have a 1999 GMC Yukon 4x4 4-Door and am curious as to whether the onboard computer can adjust to the extra lift provided by a set of 1.65 or 1.7 roller rockers. If the computer can not adjust I was thinking of getting a programmer to make the adjustment. Although for the price of the programmer, I could remove the tuned port injection and install a 650 carb and really reap the benefits. My question is has anyone on here installed these mods with any success and what problems have they incurred. Thanks in advance for any replies. They are greatly appreciated.