Had many of cars from him Chris - My 12v Auto 1993 vintage was from him.. Still got her and 40k later!
The 2.5 has NO ROOM under the engine bay, they are as FULL as the V6 engine bay,,,
The water rads, of which there are two are EXPENSIVE when they go, oil coolers also can leak, but I think this is also a 2.1 small problem.
2.5's are not particularly economical, to 30's were as the 2.1's can do more...
Not even I - as much of a DERV man would be happy with a 2,5, I much prefer the 2.1 and only have 1 rad too..
However those said, an AMAZING engine!
Rgds
Paul