· Registered Loser
I've banged mine out of the hole with a 150 shot countless times and my cylinder walls don't look like that, even after 60,000 hard miles.If it's intake side on the drivers bank I'd say you didn't have enough revs before hitting the cheater gas on your 4" stroker. If that is the case you could confirm by removing the passenger side head and checking for scratches on the exhaust side of those cylinders.
Intake side on the passengers bank... might be rings as said above. Uniform damage like that from debris through the intake is unlikely.
I'm thinking it may have been tuned super rich and the extra fuel washed the oil coat off of the cylinder walls. Either that, or the ring gap was set too tight for nitrous.