It doesn't seem like you have an overheating engine, only a hot steering column. If that is the case, then it makes no sense to change to a waterless coolant, like Evans. As to the steering column getting very hot, I have not experienced, nor have I had anyone ever tell me, that headers transmit that kind of heat into a column. If that is the case, it might be cheaper to try a header wrap first. If it works, then look at some ceramic coated ones.
