230 that's pretty warm, plenty warm enough to cause vapor lock, which is more than likely your running problem.
I'd start with a 160 thermostat and next a HV aluminum water pump.
Also, if theres to much anitfreeze it the cooling system it will run on the warm side, glycol doesnt depsipate heat as well as water does.
Run 15% antifreeze to 85% water ratio for corrosion protection then add a pint of red line water wetter, that stuff really works.
Goodluck, Cp