running out of breath in the 1/4 mile

Yeah the 12 sec burn out test will not prove anything usefull. Your 360 can burn up any street tires, in first, at like 1/4 throttle. In second maybe 1/2 or less, certainly still on the primaries. You will put down less than half power, and maybe half to 2/3rds rpm.If your brakes can hold it, she ain't putting out.

But man, you are living on the edge with all that rubber, or rather all those gearclamps, on the pressure side of the pump.
Also in your case the tank vent is very important, on account of that long flex line from the frame to the pump. Any good pump will suck that flat without venting.
Also the brass fitting at the carb; is it adequately sized internally? That one looks aweful iffy..
Also, I dislike those little gear-clamps. On the suction side they often allow the pulling of air, and require a second clamp, rotated 180*. This is especially important at the little jumper by the tank. That rear-most line needs a close watch and double clamped for sure if gearclamps are used.
I completely eliminated all rubber on the pressure side. I plumbed 3/8 line to within about an inch of the pump, and jumpered there with EFI hose. I installed a large canister metal body filter at the back with tube fittings.I ran that rear line right up to the modified sender line, and jumpered that with EFI hose. I fabbed up an all steel line from the pump to the carb. I installed an engine restraint to prevent unnecessary, and unwanted, engine movement. I run the Hi-po pump.I have no problems to at least 120mph, and at least 7200 in 3rd.Have not tried faster or higher.
Oh yeah; if the pump sucks air, well, you can't make power on air alone.