You can cut and shut the swimmer pump arrangement into a carby car tank, but you will suffer fuel pressurisation problems, fumes in the car and pressure build-up behind the cap, if you don't copy the same venting arrangements as the EFI tank. If you can bolt in the entire set-up including filler neck, pipes etc from the EFI car to your carby machine, do that. Save yourself the aggravation and the hassle if not always the expense, in this case.
Cheers,
Mitch.