Interesting, why take out a 2.8 and put in a 2.5 which is a smaller engine and has less power. I would stick with the 2.8 since that would be downgrading your car. If anything, why not a 3.0? If a 2.5 will fit, a 3.0 will too, the two engines are very similar.
2004 BMW 330ci Silvergray Sport Package, Cold Package, Xenon Headlamps, Premium Package, 6 Speed Manual, Build Date 9/03
Sold - 2003 325i Sedan Japanrot 5 Speed 8k Xenon Headlamps Build Date 11/02