And at Small Ford Sunday there were more RS2000's there with twins than the original carb... but that does not make them legal - just common and if RWCed with them the owners / mechanic ignorant and potentially liable to BIG fines!!!

EFI should be easy to pass the ADR27 tests (depending upon cam overlap too!), but it will cost you $$$ to get the proper test done to prove it complies. If you can utilise factory setup, then the factory setup will comply with the relevant years ADR's and therefore the back install would too.. They only got harder in Aus not easier, so a later factory engine / injection setup passes the earlier ADR's.

PS - if you stick a 2l Pinto originally from a Mk2 Escort into a Mk1 Escort - your Mk1 Escort will need t comply with the ADR27A ADR's from the later engine... Your car needs to comply with the later of the chassis or donor engine... (ie a Flathead V8 into a 1979 Mk2 Escort needs to comply with the 1979 Escorts ADR27A - a late model LS2 engine into a 1979 Escort will need to comply with the late model ADR's applicable to the engine in the donor Crummydore - ie fuel injection, cats etc etc...)

Bet that fact stirs a few emotions!