I used an intake and carb from a 78 mustang...and the head on mine is from a 89 stang...and the block was a 87 Ranger FI with no fuel pump slot...the 2.3 from a 78 would probably have to be rebuilt...unless it is low mileage, and even then you may be looking at worn seals and other parts that are likely to fail...
But if you can find an intake from that model year, then you're probably looking at an Offy type that are very good...the FI intakes from some years will also work with a carb adaptor...there are several threads on that in this forum...although they haven't surfaced for a few months...look under Kenny S posts and check out his setup...