Thanks. The paint is 6603 Early Gulf Blue. The car was originally a paint to sample car. Depending on the light conditions it can look as light as pastel blue or as dark as something approaching Oxford blue only without the purple in the paint. I like it a lot.

Hey Scott K. When you say 2.7S heads are great for this application, do you mean '74-'77S heads? I haven't checked them out figuring they were detuned from the earlier engines. Am I also taking a chance with any old 2.7S head? I've read that these engines ran much hotter with the rudimentary emission control systems they had in place at the time. I've been told to be cautious about using an engine case but I'm not sure if this advice would also carry over to the heads is they were affected by the heat in the same way. I guess not since the cases were all magnesium while the heads were aluminum.

An external oil cooler... I was kind of hoping that I wouldn't have to go down that route on account of where I live - it never gets much above 80 degrees here in the summer. It's good insurance I know though.

I dug out an electronic copy of the workshop manual for early 911's hoping to find out what the measurements of the heads were on the E and S (cc size, int/exh size, ports, cam duration/timing etc). Oddly, although the manual contains a staggering amount of data, the only numeric data they listed about the head & cams was for the cam timing. For those interested this is what it says:
Valve timing for the E-spec cam: inlet opens 38 deg. BTC & closes at 50 deg. ABC. Exhaust opens 40 deg. BBC and closes 6 deg. ATC.
Valve timing for the S-spec cam: inlet opens 38 deg. BTC & closes at 50 deg. ABC. Exhaust opens at 40 deg. BBC and closes 20 deg. ATC.
Only the exhaust stays open longer for the S-spec. I was surprised that that was the only difference.

I found intake and exhaust port sizes: T 30mm, E 32mm, S 36mm. Scott K, I can see why the 35mm port size of the 2.7S looks so appealing now.

Does anyone know what the cc size is of the 2.2E/S head? Also does anyone know what the measurements are for the intake and exhaust valves?

Thanks everyone once again for all the advice and direction.