Yeah, I did it. On my El Camino with a built 350hp 355 SBC I used dual HP Cats from Jegs and had a custom 2 1/2" exhaust with flowmasters. Like the man said before: cats won't cover a bad engine or state of tune. On my 355, I used a Comp 268 cam and a Holley 600 and a stealth dual plane....had...