Nikolas,
If you run the chance of spinning a bearing, which the stock lower end does, it will cost a hell of a lot more to fix than $600. So, you need to ask yourself ... spend $600 now or run the risk of spending much more later. I would opt to invest in piece of mind and get the tri-metal bearings for the rods. The main cap bearings are the same IIRC. Or, you could get the cheaper more fail safe piece of mind of an Acupump Oiling system, or both. Otherwise, you still run the risk of spinning a bearing depending on your driving style. I know that I drive the piss out of whatever I get (poor Escort), so if I where doing this, I would buy all my insurance up front so to speak.
Also, unless you add a spacer between the UIM and LIM, the UIM for the 2.5L heads will not fit the 3.0 because the 3.0 Valve cover will get in the way. So, you must either have a custom spacer machined or you must modify either the 2.5L UIM, or use the 3.0 UIM & LIM and get a hood buldge/scoop fitted because the entire 3.0 longblock will not fit because the UIM will hit the hood about 1-2 inches from closing. I would opt for a rebuilt 3.0 Longblock with a nice hood scoop ... this will help keep the heads cool, just have to accomodate for water pooling in the spark plug gallies because this will cause them to rust in place. By scoop I mean Impreza sytle hood scoop to cover the hole you are going to have to cut into the hood to accomodate the 3.0 UIM.
