Sherline - vs - Grizzley Mill Conversion (First Conversion)

Much research and great advice from this list have left me with what
probably should have been my first question of all.

I have a Grizzley Mini-Mill and also a Sherline that I can convert.
Considering Price to convert versus capability of the two machines.

Which would the list consider a better first cnc conversion project.
I primarily will be building Miniture IC engines. The largest will
probably be something like Ron Colonna's Offy 270. Probably no
projects will exceed this size.

Thanks in advance for all view points.

Alan Trest
Pensacola, Fl