You need to find the problem.
Lower rear gears and spark plugs won't fix a carb problem.

There are two things that will make it sneeze back when you punch it, slow timing and/or a lean condition.

10 sizes larger on the jets is crazy. It may eliminate the symptoms but the problem still exists. Seldom does any motor with a Holley perf carb need more than 4 jets sizes up.
My first guess is you have a problem with the power valve circuit. A bad power valve, a power valve with too low of a rating, or a stopped up passage.
My second guess is it's lean on the accelerator pump circuit. Nozzles should be big enough if it doesn't sneeze when you hit it from an idle. Make sure have a pump cam that still has travel from half to full throttle.
If you want to eliminate the chance it's the secondaries opening too soon, disconnect them and try it on primaries only. BTW, the spring has only a small effect of when the secondaries open. The main control is something called a kill bleed. Although one will effect the other, basically, the kill bleed controls when the secondaries start to open, the spring controls how long it takes to get them fully open.

Remember that there are 5 fuel delivery circuits in a Holley.
-idle ports, from the idle mix screws
-transfer slot, near the idle ports
-acclerator pump system, delivers fuel to squirt nozzles
-power valve system, delivers fuel to boosters
-main jets, delivers fuel to boosters

The goal is to find and fix the problem, not just eliminate the symptoms.
You have understand how something works before you can fix it, GRASSHOPPER.