Modern Vespa

In your GS 160 - are you running a stock motor, or did you (or do you plan to) swap it for a P-Series motor? Or is your intent to keep it original?

I know folks with P200 engines in theirs.

But i'm personally keeping the original GS engine, but boring it out to 180cc and running an SS180 piston and SS180 crankshaft.

From the outside, it will be completely GS looking.

Thanks for the info.

I was just reading about the motor mounting points being the same as the later large-frames, and hadn't ever thought of that possibility before.

Are their any realistic and preferred motor swaps for pre 1962 Vespa models akin to that of the a P-Series scenario mentioned above?

You probably wouldn't want to put a GS or SS engine into an older scoot unless you had one laying around. Save those engines for the people who actually HAVE GS's and SS's. It's not that they aren't awesome engines ... it's just that you might as well get something that's 12volt, electronic ignition, and kitable. Any engine that IS those things ( P200, T5, Rally200 ) or lets you do those things ( any p-series, Sprint Veloce, GTR, ...preferably any 10" 3-port engine ...and then at worst case a 2-port 10" engine that you can have someone build up some meat on the cases and cut you a third port )

original engine in ours

The GS/SS engine is a bit wider than the other large frames.

I p200 can be put into a GS and most will not notice the difference (though many will). That extra width prevents the GS engine being put into another model.