new engine same electonics... re-dyno tune?
 

So replacing my engine with a newer used block and head. I'll use my same exhaust. Same throttle bodies same filter same injectors cpu etc....

But new block new head.

Will I need to retune my power commander or will it make no difference since the mechanics should be same other than wear?

It should be pretty close to the same tune.

If you want it perfect, put it back on the dyno.