Scott Daniel - Turbovans wrote:
> the only real difference I can think of on the whole long block is the
> extra oil pressure switch on the 2.1 .

Actually, Scott, there are two differences.  One is the additional oil
pressure switch that you mentioned, and the other is where the plenum
bracket bolts to the case near the flywheel.  To use a 2.1 plenum on a
1.9 case you either need a spacer or you need to reshape the bracket.
To bolt a 1.9 plenum to a 2.1, you need to reshape the bracket.

Mike
With a 2.1 engine in an '85 Westy (using a 2.1 plenum, though).