Engine smoking

New to the forum so here we go

i have a 72 dodge dart swinger that has a 1988 318 in it, my problem is that the # 5 cylinder is sucking up oil alot, changed the valve stem seals which i thought were the problem but it wasn't, checked compression on it and it was close to the same as the others and i even switched spark plugs with another cylinder and ran it for a little bit and it was oily big time, i suspect the oil ring but i was wondering what would be best. to rebuild the whole engine or just take the head off and take out #5 piston to change the piston rings?