I have found few engines and am wanting to know what are the differences in the year ranges of this engine.

I think that makes sense.

 

You will want an 96 thru mid-02 engine. Somewhere in the middle of 2002, GM changed the engine over to the new vin X engine which did not have the traditional EGR valve, had the upgraded MFI spider injectors and had revised machining for the knock sensor in the back of the block.

 

What was different on the earlier engines other than the intake?

 

Anything earlier than 96 is cpi/tbi, etc. The 96+ have a plastic manifold and Throttle body that isn'tremovable its integrated to the manifold like 95's and below.

And everything you wanted to know on the 4.3L

http://www.enginebuildermag.com/Arti...chevy_262.aspx