Disappointed with my engine

That cam is wrong for zoomie headers. You’ve killed all the power because you have killed any flow at overlap with those headers. You need a good, tuned header with the proper size and length collector. The other thing I see is that carb hat. I don’t know how many square inches the opening is, but it’s too small. Also, with that style of scoop you run into an issue where that scoop will pressurize the vents and it will go dead rich. You’ve got issues, but most are easily corrected. And the carb is killing you. A vacuum secondary carb is for guys who can’t tune. There is a real possibility the secondaries don’t even fully open.

Tell me more about this pressurizing the fuel bowls/vents idea.

Years ago we ran one of those tall econo dragster scoops sealed tight and picked up 3 tenths and 6 mph (1/4 mile back then). We didn't make any change to the carb.