Truck cranks but won't start
 

I have a 97 f150 4.6 it blew a head gasket and I got a 4.6 out of a 97 f250 both Romeo's I used the wiring harness off the 250 not sure if it's a difference. I got it all hooked up except running water with it just to see if it runs but all it does it turn over. It has spark and fuel pressure and it only starts if i spray starter fluid in it and it cuts right back off, does anyone have any ideas as to y it might not be starting

Injectors aren't firing, confirm that with noid lights. I'd guess that it's not wired correctly.