Works great, and without headers.... watch the 1st minute. I run a 750 double pumper on my 360. Even when it had stock exhaust manifolds and stock heads, it ran the best ET at the strip (over a 600 eddy, and a vacuum secondary holley). That was with 2.45 gears and stock converter. My point is the 800 may not run faster than the 650, but it shouldn't give anything up to it either
