depending on the sides it can be alot or none modification. but they ARE teh same length yes.. one of my import fighter sides is off a 4dr.
they didnt make different wheel bases between the coupe and seden so yes the sides from a 4dr will fit a 2dr and visa versa, however they have to be side skirts like the bc2, import fighter, etc... sides like the drift kit or trd sides will not fit a 4dr do to the rear door.
