converting a 4x4 trans to 2x4 involves disasembly of the tranny to replace the output shaft. putting a 4.3 in place of a 2.2 has been done several times. what do you really want to know.
You're post is confusing but I think you want to put the 95 4.3 and transmission into the 98 2.2 truck? My first instinct is to tell you that's a complete waste of time as its a 160hp TBI motor. 2nd instinct is to tell you again that it's a waste of time and effort. 3rd instinct is to tell you that it'd be way simpler to just get a 2wd trans. And finally 4th instinct is to tell you to sell both the blazer and 2.2 and get a stock 98+ 4.3/2wd truck.
Im going to have to agree with this guy. Why combine the two. Just sell and buy what you really want instead of wasting time and money.