what do I need to do to swap a 5.0 efi into say a 90 4cyl body

 

first sell your banger. take that $ and stack it to say 2-2500 and get a clean 5.0.
believe me thats easier.

 

you will need a full drive train for a 5.0 for one,the you will need a 90 mass air engine harness,o2 harness,and head light harness.You will also in to swap the fuel lines or make custom lines like i did and you will need a a9l or a9p ecm.there is a lot of lil things that you will need your best bet is to get a wrecked v8 car and swap it all over but if this is going to be a DD then just sell the car a buy a stock v8 you will be doing a lot more then you think.