Can i easily swap a 302 ho from an 86 mustang into a 84 mustang?

-i have an 84 mustang gt with a 351w and i wanted to swap the engine with an 86 efi 302 i talked to this guy and he said i would have to change k members and all that good stuff. is it as simple as dropping it in or would it be a big project? (minus all the wiring)the 84 mustang did not come 351 of any type, some one most have put a 351 in .you said the 351w is it is almost the same block as a 302. the 351w has a taller deck then a 302 the engine mounts and trans mounts are the same so yes 86 302 will bolt right in the 84 probably had a 302 when it came from the factory. 84 mustang came with a 302, 3.8l v6 , 2.3 4cyl and a turbo 4cyl the the v6 was droped in 86 and did not come back till 1994.