yes, the 350 heads will bolt and work on the 283,,,but depending on what casting number and what CC they are they may lower you compression ratio. and yes, the 350 harmonic balancer will go on....expect you do not have the retainer bolt on the end of the 283 crank. anything bigger than what you have would scare me.hese heads are made FOR a 283 and will Yeild in the 10-10.5 to 1 compression. I would stay away from all late model heads personally. Your deal is NOT a Nightmare, Just run a Stock 283 Dampner..