Dodgeman is correct about the race engines.
I think the race cams are .441 lift and something like 312 degrees of duration. The motor will not idle it won't come on the cam till round 5000 rpms and with a 9000+ redline they only go about 6 hrs between rebuilds.Also with 14-1 compression pump gas isn't an option. A12 race engine is about 140HP at the crank and I seem to recall 175HP for an A14.
I know the distributer will fit because I have an A14 electronic distributer in my A12GX.
We use the A14 valves in the GX head with the 120Y/B210 distributer, GX cam, header, 2 inch exhaust and cleaned up the ports. The motor pulls to 8K , idles well and runs all day long with no problems. The only thing I might change is getting something a little more aggressive than a GX cam as they are pretty mild.
The race engine parts even in the USA are pricey...........although keep your eye on E-bay becuase here in the states fewer and fewer modern racers are running A-series powered cars and only a small handful of cars have been left unmolested enough to switch to vintage.Also most vintage Datsun racers run 510's Z's and Roadsters. So for guys like you and I some really cool parts will be availible and decent prices for the next few years.

Tom