I admit I don't know much, if anything, about firing order. I assume it is correct now or it wouldn't run?? I should be able to match the existing setup. When you say 1-2-4-3, where does the 1 start?
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
1 is at the radiator. Also.. these 4 cyl N engines will start on 2 cyls.. and will run reasonably well on 3 cyls. Howebver.. if ya had a wire swapped.. you'd have 2 cyls at max.. and that probably would stall trying to let the clutch out.