Double-L

I have a few questions, I have a 04 SSR that had a 5.3 with a 112 Magna Charger with a 2.8 pulley, 10 1/2 pounds of boost, Alky injection, It run pretty good for a 5080 truck, 12.70 at 108 but one of the pistons broke so I was going to build it stronger, While thinking I came across a LS6 block for a good price so thought I would just build that with some parts off the 5.3, Took the block to Lingenfelter to do the machine work and bore, I added- Eagle balance stroker crank, Eagle forged rods, JE pistons, ATI super balancer, Ask Lingenfelter for the best cam and they said for a super charged street strip LS3, Lingenfelter GTG2-2 cam, 207/220 571/578 , Dart 225 heads with all the good parts, Comp Mag 1.85 rockers, Bee Hive springs, Best push rods and their full rpm kit, Rest of the parts off the 5.3, Tranny is built right with a PI Vigilante 9'' 2800 converter, Now the problem, It is being tuned with a HPTune have a good wide band 02, First I lost 5 1/2 pounds of boost, Next the truck seems to run real good on the street, Will break the 11'' tires lose at 75 mph, I run it and it has KR all the way through 3rd. gear, I don't care how low you set the timing or if you turn the alky all the way up you still have KR, With the alky all the way up it will start KR at the end of 2nd., My fuel air is 11.5-11.1 with alky from 4-8, I looked at one of my old scans with the 5.3 and it looks like the computer is trying to make the 377 do just like the 5.3, Is it fake KR, Is the computer going to work on the 377, It runs strong but still needs some tune and you hear no knock or feel any, Anyone know anything that would point me in the right way, Thanks

Red99C5

Run some race gas in it and see if it stills shows the same KR.

Double-L

Me and the guy that works on it was talking about trying that, Put some 116 and make a run but man as low as I set the timimg and running the alky wide open, I have been told to try-1. Go into the alky controller and turn it up so you get more alky, 2. to change from a Non LS-series to a LS-series engines will require installation of 24X reluctor wheel, crank sensor, 2X cam gear and cam sensor. Other miscellaneous wiring harness mods may also be required. Oh forgot to add the 5.3 was was the same as the LS series engines
Thanks