I want to swap engines over between my NC & EB, my mate says we should get the cam grinded before the engine of the NC goes into the EB.

Would any ECU tweaks need to be done or just install the grinded cam back in and the engine will run as it does now?

Don't use a reground cam, buy a new one. However if you haven't done anything else to the engine I would leave the stock cam in it.
Just get some 1.7 roller rockers to gain some valve lift for a low buck improvement in performance.

A re-ground cam gets more power for less $ than almost any other engine mod. All the cams in Tickford AU XR8 S2 & S3 are re-ground explorer cams so it's not dodgy in any way. Over here in NZ a re-grind is $150, which can net 30-40FWHP. Lifters don't need to be replaced, only about $40 worth of gaskets. So for under $200 the performance improvement potential is huge. Just keep the base circle reduction below about 0.040" so the lifter still has some pre-load. Even better, measure existing pre-load before removing the cam so you know how much can be removed from the base circle.

The ecu will cope just fine

Thanks for that info XAfalcon.