i have done it before. its best if you have a 5.0 doner car off the top of my head here is what you will need to change,
engine and all accessories
radiator
trans and crossmember, driveshaft
rearend and the brake line runing to the rear end
fuel lines from the tank to the engine
brakes and booster 4cyl brakes wont cut it!
ecu, firewall harness, and engine harness
the 91 firewall harness will NOT work on your 93 you will need to find a later 92 0r a 93 firewall harness