Ok so my car is a 57 2dr hardtop. The motor is a 327 bored .60 over about 9.5.1 cam is a compcams XE268H match lifters hardend push rods and a set of 1.5 roller rockers. Heads are edlbrock performer RPM It's got a procomp air gap dual plane intake summit 600CFM carb with vacume seconderys procomp ignition with 6AL box and coil bought as compleat kit with the 10.5 wires plugs are champion 12YC. procomp fuel pump. gauge reads 6.5pounds B&M alum water pump radradiator three core alum radiator headmen headers (full length) 2.5 inch dual exaust with H pipe and trush turbo mufflers. I have an M21four speed with an original posi rear end 3.55 gears. I've heard a 750CFM carb would work better the only problem I've ever had is when driving highway speed 3,000 plus RPM I have what almost feels like a short cut out?! It did the same thing to me before the carb and ignition so I've kinda ruled those out it also had a holley blue electric fuel pump so I put the mecanical pump on but no differance. My carb before this one was a holley 650 double pumper so am I just not feeding this thing enough gas? Full throttle this car will burn the tire's into every gear so she runs great it's just steady cruising at around an over 3,000RPM. Love to hear from you guys thanks!