hi flow cats

[mikepage0007]

looking to put in a twin screw ,next couple months, my problem is that i need to free up some backpressure -restriction to maintain hp with less boost..ls3 ,btw...i know ,LT HEADERS, pretend that headers don,t exist, i don,t want a drag car, already have one that scares the neighborhood kids....i want a stealth car that whistles..lol...does anybody know how restrictive the stock cats are compared to high flow? also i,ve read that all highflow cats are different...there restriction is measured in cells? ex: stock cat is 600 cells , where as a hiflow cat can range from 100 to 400, 100 of coure is the least restrictive....i do live in fl , so inspection is not issue, beside i believe that hiflow cats are all legal....i have thought about cutouts b4 cat, but really don,t want to go that way...just more wires ,switches , etc....i repreat no headers..... any ideas...do all the big factory special build companies know something? .they are builing sc cars up to 800hp without headers < anyone know how there doing that without running the boost up to 15...tell me..i,m listening..thanks.