Not to try to convince you but I bought my MAC's used and they had been sitting in someone's shed for a few years and they were ceramic coated. They had some surface rust and were all discolored but I was on a super budget as I got in way over my head with the 347 build. So I bought them dirt cheap and put some elbow grease into with a power ball and polished up real nice.
But yes make sure they are Kooks and remember what I said about the mid pipe as the Kooks need their own mid pipe. Also get the collector size.
2014 V6 Deep Impact Blue Mustang, Borla Type S, 2.73 (Uughh need 3.73)
1989 Sonic Blue Mustang LX Coupe, 349 ci,
392 rwhp 424 rwtq....Mustang Dyno
"There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves." -Will Rogers-