kindly advice me i want to swap efi in my Accord 1987 without alteration pls

Hello all,

in last week i bought Honda Accord 1987 but its engine is weak alot, so i need to rebuild or swap new engine in it, so i have decided to swap new efi engine but mechanic told me that i have to alter body from front end, and also need to cut and weld for engine fitting, kindly guide me if anyone know which engine can b swapped in my car without any alteration, quick response will be appreciated please.

Is you car already EFI or is it carb?