The exhaust is 1 5/8 hooker headers to a 3 inch collector into 3 inch home made pipes. A 2 1/2 inch H pipe was put in as an after thought, it runs into 3 inch Dynomax "racemagnums" now called Ultrflo welded with 3 inch turndowns. I like how crisp that .474 sounds compared to the .508, I problably didnt need the .508 in my combo since the heads are unported and my converter is a little too tight for it. Ax thanks for posting vids of your car, its awefully cold up here right now so it warms the spirit. One more vid from me for laughs.