T2 is smaller than T25, T25 is smaller than T28, T28 is smaller than T3.
do the t25's have the trapezium bolt pattern?
nopes. a T2 ore evrithing what begins with T2xxx... from garrett got this manifold bolt pattern

I know there are manifolds wich will fit youre T2 flange, i was thinking a vw vento, maybe someone else can confirm this?

I don't know what a gasser turbo gonna do on a diesel, it will work, but maybe with more lag becouse of the trim, a/r... someone tryid this?
Can you post ore send some pictures from the turbo? specialy from the side of the downpipe?
Greetz, Benjamin