I just want to drop in place with less hassle I actually have an ex plod 3.0ltr engine so if this is the easiest option I’d gladly take it, I’m not racing it or going drifting in it, it’s for my Astra van that has a very big audio system in it…[/img]
I'd say you will certainly have less hassle with the 3.0L lump, especially if you already have one that I presume you know the condition of!
You'll still be able to use your current 2.5 ECU so there'll be no need to change the immobiliser chip in the key or make any other wiring changes.
An alternator upgrade might be a good idea though - the standard 120A unit struggles to supply anything approaching 2kw in winter with lights on etc