I got asked this question.
EXAMPLE - 1981 or older camaro could use MSD style ignition & carb. or any mechanical fuel injection & be legal.
from rule book I'd vote LEGAL.
what if U put in a late model LS series engine , crank triger, coil near plug, efi, & use GM ecm to control ?
LEGAL - NOT LEGAL ?? If not legal for CGC what class would it fall in?