Cooling a 460/Head Gaskets

[wizard]

Don't have an oil temp guage or oil cooler either for that matter but that's going to be resolved soon.
I did get a some new info as to what the cause might be and since I've;
1. Replaced the water pump (high flow).
2. Had the radiator professionally cleaned (probably didn't need it)
3. Installed a 180 thermostat (came without one)
4. Converted to 100% water
5. Verified stat is opening
6. Tried a water wetter solution.
7. Verfified system is full
the new info makes the best sense at this point.
The water temp is always 10 to 20, maybe 30 degrees hotter that I would expect for the situation. I'm afraid to push it for fear of doing some serious damage.
Thursday i heard that a leaking head gasket could allow exhaust gases to enter the water jacket which will raise the water temp. Because of the serious pressure difference, the water won't leak back the other way. Run hard and temps go up, slow dow and temps will come down, slowly. I also did some pressure tests Friday and I found them to higher that I would expect. Can a water pump peg a 30 psi guage at 3000 rpm? Should you see 25 psi with the motor idling and at temp? (Yes both my guages are reasonably accurate)
3 ways to find the problem.
1. Sniffer test - some chemical is set down in the rad or surge tank and if it changes color, you got a leak. Talk to a local guy with the tools and he's rather do a full blown cylinder pressure test at $60.00/hr It'll take him an hour just to pull the plugs.
2. Talked to an engine builder friend and he can do the pressure test. I trust him plus I can assist which could help keep my costs reasonable.
3. Go ahead pull the heads and inspect the gaskets.
I'm opting for #2 if I can't find someone else who can do the sniffer test. I've learned over the weekend that there may several others locally who have the equipment. If I have to go with #2, it may be a week to 10 days before he can fit me in.

Right now this seems like the most plausible scenario consistent with my symptoms and knowing of others with 460's and 514's that run a steady 180.

vettestr out in AZ has been a big help with suggestions but anybody with opinions one way or another, jump in, PLEASE. I would especially be interested in water pressure readings at the manifold just ahead of the stat to help determine if my suspicions are correct. Actually if readings are way out of bounds, that in itself could be the smoking gun. Where else could the pressure come from.