I guess my first response did not post.
I had written that EFI is NOT allowed in the Classic classes. IF you use an EFI unit it MUST be for the body used. In other words, if you build a '53 Chevy and want to use EFI the unit must be the 1953 OEM piece.
To expond a little further. There are no Classic engine classes. There are available Vintage engine classes, XF, XXF, XO, XXO, V4 and V4F. All other engines are just lumps of various displacements. The Classic classes are based on the bodies used and all rules will apply to the body, not the engine.
Why is it this way you may ask? When the Classic classes were formed, a three year+ project, the proponents of the classes wanted separation between the Classic and Modified categories. As usual, cost was sited as a major issue in running a Studebaker against a late model Firebird. The classic guys wanted no EFI and no data logging because of cost. The data logging restriction went away last year because a guy with a flathead Model B engine in a Vintage roadster had the use of the technogy and a Classic car did not. The fact that available data logging units have declined in price is a factor also.
The restriction against EFI is what keeps the two categories separate. Much like the F/G Roadster vrs. a Street Roadster. There are class specs that keep each type of car from running cross class.
DW