Re: swap chevy 3 L for 2.5L
The swap would be virtually a direct swap, the block is basically the same, so as far as bolting up, it'd be fine.
The only thing I can think of would be the manifold. The 2.5 head has a different port setup than the 3.0. Many will tell you its a direct swap, but I'm not 100% convinced a 3.0 manifold will work on a 2.5 head w/o and problems.
See for yourself the differences:
If your motor is like my 3.0, the riser is curve shaped and not hard angles (like the older 3.0s and 2.5s)... I'm not sure if the 2.5 manifold and 3.0 curved riser will work together... and I'm fairly sure that the standard 2.5 riser won't directly fit the piping meant for the curved riser either; Someone else may know better...
Just trying to help you out - I was in the same 'boat' the last 2 months, looking for parts.
