Hi, just bought a Silverado that needs another engine (the old one threw a con. rod). What mods. do I have to do to get an 2000 S10 4.3 to fit? any advice is welcome and thanks!

 

Yes that same 4.3 engine will fit your 2001 Silverado.
The 4.3 L has been in use since 1988–2003 in the Chevy Silverado/Chevrolet S-10/GMC S-15

 

As far as I know, just keep all of your Silverado's accessories brackets and wiring and just swap the block over and you should be fine. I don't know if there are any other internal engine modifications between the two trucks though.