Upgrade F162 to F163?

[old jupiter]

I see in the specs that the compression ratio (before carbon build-up) for the F162 in my new-to-me 1954 SA200 was about 6.0:1, while for the F163 it was about 7.4:1. I might do an overhaul on this engine, and it would be silly to miss any useful upgrades I can make to it while it's apart. All else being equal, increased compression yields better fuel efficiency, among other effects. Flatheads tend to be gas-guzzlers, and being able to run longer before refueling is always desireable. Would anyone here familiar with both engine models care to advise me on upgrades that will help an F162?

Incidently, my machine has the Wico X magneto, which evidently is not found on many of these rigs, and isn't much discussed. It might prove to work fine (I got the welder for $200, and am doing some preliminary fix-up before I try starting and running it).

Well, here's another question. My machine evidently did not have a pressurized cooling system, but does have quite a big heavy radiator for an engine that size, at least by automotive standards. I know it's heavy because I just took it off the machine and boiled it out in a caustic soda hot-tank. In the sticky I saw reference to a 7lb pressure cap; was that being suggested for use on a factory non-pressure system? Was the non-pressure system marginal for cooling? I see somebody selling eight-blade fans (mine is a 4-blade) . . . .