ive seen 3 cvh turbo engines in the last year that the timing belt was a tooth or two out causing the same problem

ive seen them with all the valves bent and made a simular problem but it would not idle if that was the cause so at least i can say in my experience it doesnt sound internal, but electrical

you say you converted to efi but then mention a dizzy cap? wouldnt it be fitted with a coilpack? does sound like a coilpack/ incorrect firing order or something along those lines.

ive also experienced a alternator electrical drain that would cause a misfire on boost but you say its as soon as you rev it?