Neither of your issues sounds good. I have the Transpo voltage regulator and haven't had any problems.... but something is causing that insulation to melt. Is it the proper gauge wire? Those Transpo's are very sensitive and can blow quickly if there is an electrical short. As for the anti-freeze... any of that stuff on the outside of a motor indicates a leak! If you suspect a head gasket, what does the oil level and oil look like?
Phil
427 Roadster, #4279436
FE Specialties FE
3:31 and Toploader (wide ratio)
Roseville (N.Cal)