Hope someone out there may have been there done that. Just swapped a 5.3 to a 6.0 in a 2K GMC, it runs fine when you put your foot in it, it would have 15 degrees timing at WOT and 7.9KR.Called EW talked to John he said you need a custom tune in order to make it run right. Got there tuning and now it maxes out 20-21 degrees at WOT.And with all the KR.Its something outside of the tuning i can just tell it in my gut, something maybe i did.I oh <img border="0" alt="[Truck]" title="" src="graemlins/gr_truck.gif" /> <img border="0" alt="[kaboom]" title="" src="graemlins/gr_bomb.gif" /> med out the KSs and they were fine.Hooked another set of KSs with a harness,grounded both sensors, they were not touching anything drove it and got the same results,something is pulling timing and its not the KSs.Ed is stumped, i am missing a ton of HP, the rest of the time the timing is going up and down like normal, just at WOT or light throttle lugging the engine it will get full KR,resistors and knock out boxes wont have an effect. HELP ME PLEASE