Originally Posted by tabetha

No, HG should be ok, don't just stick a higher rating cap on there, they are designed to keep a certain pressure and no more, all systems have an expansion area, on older cars with no seprate bottle it was the area above the cooling fins in the rad not occupied with water, it the water level rises taking up this space, the level only needs to be visible above the top row of fins, just so you know it has enough, so leave it there, water expands as it heats up, if there was no area in which to expand, the pressure would easily blow the HG, what fan/cooling arrangement are you using, as this should also be kicking in when hot enough.
It's suicide to run without a temp indicator.
I would look at these things before upping cap pressures, the front two bolts should really have an extra 15lbft, this stops the oil spaking through the HG.
tabetha