Volvo Repair: Head Gasket, head gasket, volvo dealer

Question
1991 240 Volvo Sedan 145,000
The car has been heating up to the orange line when going up long hills (we live in the mountains). So far we have changed the radiator (I think it was the original and was almost totally clogged), but it still has the problem. The coolant had 20% florocarbons, which we have been informed is the probable result of a cracked head gasket. Could the engine still be overheating because it needs a new head gasket?  And to change it, do I have to remove the timing chain, then redo the timing?

Any help you can give me would be greatly appreciated.

Answer
well yes, it could be a head gasket, and yes you would have to remove the timing belt and redo the timing. but before you go to that expense visit your local volvo dealer, get what is known as a temperature compensating board. this little bugger lives in your combined instrument panel, and can cause actioins such as you described to happen with your temp. gauge. its a fairly common thing to fail, and if it saves you the expense of a head gasket, it will seem relatively cheap at that point.