a 240 or a 340 is a MK-2 with a 2.4 liter or 3.4 liter engine, otherwise it is the same car as the MK-2 before it, with some differences like vinyl interior instead of leather, thin bumpers, the front bumper is the same as the S type, the rear bumper is exclusive to the 240 and 340.

yes you can install a 3.4 or a 3.8 liter carburetted engine in the 240, same engine compartment. In fact you can install a 4.2 liter carburetted engine if you want.