Just call your local G.M. Dealer parts counter... They'll have the answers to wich engine, all your injection.sensors & ecm will work fine, looks like in 95 they had a 350,454 or Deisel, This should be a straight forward swap,but I suggest you replace the oxygen sensors while ya got it out.....If'n ya use the high output engine you might have trouble with the emission test cuzz of the cam overlap, Call several dealers and get the prices every one of em will be different.