The lower IM's are the same for 3L and 2.5L except for one mounting boss for the fuel rail, and the linkage arm for the secondary butterflies.
Yes you can use the 3L lower, but it must have a way to bolt down the rail and the linkage needs some small changes.
The point of me posting this is why would you? The 99 and up SVT lower's are already the same size as the 3L lower, with the addition of xtrude honing. In effect you would be losing out somewhat if you go with the 3L.
warmonger
