351 W
The only difference is the intake, ignition, and the fuel pump is electric instead of mechanical. so you will need an earlier timing cover. Otherwise your early ignition and intake will work. The compression chamber size was 60cc up through 74, and had 1.85 intake/ 1.56 exhaust valves. Your mid 80's heads have a 69cc chamber and 1.78 intake/ 1.48 exhaust valves.
Other than the fuel system, ignition, and fuel pump, the later 351 is a bolt in.
If you were going to run the earlier intake manifold you would have to plug two bolt holes on each side, as the early intake had 8 bolts per side, the later ones have 6 bolts per side. You can use a later model or 6 bolt intake on the earlier heads, with no modifications.
The bolt holes to plug would be 2nd and 7th on each side.
All 351W's have a 9.5 deck height.
As for the cam, I recommend contacting Camresearch in Englewood, Colorado. They are Ford specialists, ground the solid lifter cam I have in my 351W.