Personally, I think it sounds bada**.
lazer is correct, it's an HPE 434 with stage 3 AFRs, 11.5:1 CR, Kooks 1 7/8 LTs, FAST 90mm intake, yada, yada...and a big cam (254/262, .640 lift, 112lsa).
Made 562rwhp and 507rwtq.
And no it wasn't running thru the exhaust...the cutouts were open...