A friend just sold their M20C, I think it was an early 60's. I'm 6'2",
185. Way too tight for me. Much smaller cabin length than the 64 S35 I
just bought. As for speed, no comparison. The Mooney in really good
shape might get 150 kts, my friends flight planned 140 on about 10 gph.

10 gph seems extreamly high for the 180hp C model Mooney. I have a
student with a C model and he usually sees about 8.5 on the fuel flow
JPI. My 200hp Mooney will run about 9.5 at altitude. I'm not any faster
than the C model but I've got a longer cabin for the kids in back.

My Bo gets 175 kts if you want to run 15 gph thru it. The main thing
about the Mooney is you really have to keep it on pavement.

Personally, I like to land mine on the beach. I've gone into
Alphonsinas, Mexico many times (hard pack beach sand). I've got
pictures of a couple Mooney fly-ins at Mulege's dirt strip too if
you're not convinced.
The prop clearance looks to be about 2" from a distance. However, an
actual measurement shows it to be something like 18".

-Robert