You might be able to get away with some sort of an adapter for the caliper, then drill a four-lug pattern to make the rotor fit, but I'd go whole hog & do the 5-lug swap.
The 5-lug swap for the e30 uses a bunch of parts to make this happen. On our side of the Atlantic, the later model e36M3 (1996-99 IIRC) had slightly shorter control arms.
From what I've gathered, you'd have to:
Press new e30 ball joints into the later model e36M3 control arms
Use e30M3 offset control arm bushings
Be sure the M3 has the skinnier (96-99 model over here) front coil springs, the fat ones are too wide for the e30 towers
Use the e30 upper strut bearing cap with the M3 struts, knuckles, etc.
Of course, you'll need the whole rotor, brake caliper, etc.
The back is easier, find a Z3 M52 to donate the rear suspension. It's similar to the e36 Compact (318Ti over here) but has larger bearings and maybe even a torsen diff.
Some people reported problems with the e30 ABS, and you'd have to sort the master cylinder too. I'd attempt the 750iL master swap at the same time. Your e30 would stop & handle much better after all this work, I'd assume.
Topic: [E36] M3 front hubs/spindles on a 318iS (Read 3009 times)