Possible to put a 1991 318 fuel injection on my 1973 318?

I am pretty uneducated when it comes to Fuel injection so I have to ask. I see 88-91 mentioned. My question is, when does the fuel injection get better? I have a 92 5.2 complete with harnesses, trans and all. I was thinking about dropping it into a 56 suburban for reliability/drivability. Sorry for the hi-jacking, not my intention.