clickity clack

my 318 makes a clacking sound around 2700 rpm on highyway the motor is tired but im trying to baby it until i can afford swap or rebuild as it is my daily driver i have played/messed with timing and motor seems to run fine to me but i am no expert it seem to crank well otherwords it fires right up it does smoke a little if i accelerate but i dont realy do a lot of that hard[ not yet] it also smokes a bit when firing up cold so where should a poor man put his cash first thanks