Pontiac Firebird 1967-2002 - Headers with ORY 2002 trans am

If I buy Hedman headers (standard size) with pacesetter off road y pipe, will it be long enough to cancel the cats? Or would I need a different midpipe or something to reach the muffler

an off road y pipe is the Y pipe without cats on it.

If the headers are long tubes then yeah it'll delete the cats with the ORY. What's standard size? (Shorty, Mids, Longtube?) I've never heard that before