Got new motor back

Well I finally got my 351w block back from the engine shop that cleaned and balanced it for me. The engine came from a 84 pickup. I was hoping to be able use the heads but after inspection there were small cracks that the engine shop said would give me problems with down the road. So now i need to ask if I go ahead and purchase some nice new heads will it mess up my configuration. My Bronco is a 91 with SD. I had found the intake parts from a 5.8 and was going to use it and the egine and heads from the 84 pickup which was carbed. After reading posts on here i'm not sure if putting aftermarket heads will give my SD system problems. My other option is to look for junk yard heads and hope they are in good shape. I do like the idea of having better exhaust flow with aftermarket or GT-40 heads but don't want to make things to complicated.