Your initial post left me to assume that your were concerned about "basic" interchangeability between the pictured manifold runners, and whether the differences were merely cosmetic. (Curiously, the parts book describes these runners as "suction pipes" and "intake tubes.")
FWIW, typical E9 runners are PN 11611256567;
E21 runners come in two flavors: PN
11611264725 and
11611264723 and
2002 tii runners(metal) are PN 11611251348
I would not try to dissuade anyone from experimenting with different sized runners. Nevertheless, one wonders why none of the the factory M30 (six) engines used the same E21/tii runners.