When you say hard to start do you mean it turns over slowly? Slow to fire off? It could be several things as these cars are rather finicky. Make sure all your power and ground cables are in good shape, that you’ve got the proper 3 port fuel pump with return line and pump heat shield (provided you’ve still got the 462 MEL engine) or an electric fuel pump upgrade.
Often the correct 3 port fuel pump is the issue. Parts stores don’t have the correct one, it’s a two port and a cobbled together return or no return feed at all. Finding a rebuilt correct OEM pump solves the hot fuel boil off/vapor lock problem these cars are plagued with.
Also make sure the fan clutch is in good shape, the radiator is flowing well, the radiator shroud is intact, and the timing is set properly.
Resistance is Futile.