On Timing Chain Tensioner, consider one of those "ratchet-type" tensioners that don't rely on oil pressure to tension. This was a consideration when I paid to have my new block installed (thanks, @Cruiserhiggs !), and it can be replaced from outside without too much trouble, but in all...
Back to the question at hand;
Harmonic Balancer
Radiator (TYC1918 for me)
Main wiring harness to engine
Knock Sensors (2)
Engine Mounts
The rest can be reused until it naturally fails, and these parts are the ones to put in with the engine, because it's easier to do so now. It's what I...