ls swap in square body running poor

[cr92]

hey all,

recently swapped a 4.8 vortec/4l60e in my 87 chev r10. having some idle issues and its not running very good at all in drive. i followed the wiring harness setup through lt1swap.. but it seems like its running hot on bank 1 with MAF sensor plugged in... it was shooting sparks and i could see inside the cat was blood red ( exhaust only reaches past the catalytic converters)

when i unplug the MAF it idles good but you can see a bit of black smoke coming from it so it must be running rich.

donor truck ran good before swap, drove it 70 miles no problems. only thing i can say is that the map sensor got broken from the engine hoist plate we had mad so i replaced that with a map sensor someone gave me from a 5.3, the part numbers are different but on rock auto they cross reference so that should be fine..

tried swapping MAF sensors with a good running ls swap, different map sensor, different computer, checked spark plug wires for spark, 02 voltages with MAF plugged in were around 450mv on bank 1 at idle and were pretty much showing 0mv on bank 2, and then with MAF plugged in was showing 450mv on bank 1 and around 150mv on bank 2.. seems a bit low to me..

Fuel pressure was showing around 43psi with key ahead then dropping to 15psi after a few seconds, 43 psi steady while running. we checked my friends 5.3 swapped square body and his is showing 50psi key ahead and running. and a 2012 5.3 which would show 67psi key ahead then 45psi running and it runs perfect. those numbers seem low but both other trucks except for mine run and drive great? i tried the fuel pressure tester on my pontiac g5 and that shows 58psi constant key off or car started so i know the gauge is working?