"Id mostly just like less fumes"

I have a convertible that used to have bad fumes issues, and it was efi'd. The large roller cam kept both valves open long enough so that it would burn your eyes and irritate most anyone that happened to be near the car at idle. It idles very close to 14.5 to 1 AFR too.

I run a warmed up 408 Magnum with a full TTI 3" exhaust with cross over, so I ordered up a pair of high flow, 3 inch inlet/outlet race only cats with a metal matrix and a 4 inch thick main body, welded them on just after my collectors and the car was clean of fumes from then on. They flowed so well, I never felt a power difference, even at full throttle. I was actually pretty surprised at how well they work and that the car didn't slow down.