Seeking troubleshooting experience

[Tom in TN]

Y’all, I am puzzled, My little hot rod has “issues” and I need someextra knowledge and suggestions.
First, the details of what I have:

1934 Ford 5-window coupe – my dad bought it in 1958 and sold it to me in 2001 for a dollar.
Engine = 1936 Ford flathead
.060” overbore.
3 / 4 race cam
Aluminum flywheel
Eddie Meyer finned heads
Fenton open plenum aluminum intake for 2 carbs
2- Ford 94 2 barrel carbs w/#50 jets and idle mixture screws at .75 out.
Mallory Dual point crab-style distributor- 2002 - 2010
Accel Hi-Temp Super Stock radio suppression core 8mm yellow plug wires- 2003
Stock exhaust manifolds
2003 Walker radiator with Cooling Components electric fan/shroud
12v system

Current status- it idles just fine. I can drop the rpm so low that you can almost count the cylinder explosions. I took it out for its first road test since replacing all wheel cylinders and the master cylinder and converting to DOT 5 brake fluid; and replacing the gas tank.
It started down the road fine- hitting on all cylinders, but then it started to miss a hit or two, then it missed a few hits, then it would run ok for a piece, then go back to multiple-misses. Made it to the non-ethanol gas station and filled her up.
Left there and the same scenario happened again, when I pulled away from the station, it was hitting on all 8 and then the missing started again- extremely random- HIGHLY annoying.

So, I am looking for knowledge and experience to tell me: How would YOU go about finding out why it is randomly mis-firing under load?

Any and ALL suggestions would be greatly appreciated.
Tom