I have a 76 Nova race car. Its is going to get cold here in a week or so and I have to keep it outside this winter all tarped up. What I did, was pull the rad hose off the water pump and let all the water come out of the rad and block.Put the hose back on and filled it to the top with pure antifreeze. Fired it up for 5 miutes then turned it off and covered it up. I was wondering if this is enough for -25 celsius? Or is there trick like a lighbulb or somekind of heater I could put on the engine for the week or 2 of cold weather? Just nervous about crackin a block...

I know that they do sell a product in colder climents to keep engines warm. It's an electrical unit that plugs into a socket. It's an engine blanket. If you lived in say Minnesota you wouldn't be asking this question as your local auto store would certainly carry them.

Regardless the latitude or temperature, you would do best to park your ride with the cooling system filled with the proper mix for your vehicle.
Most cooling systems will corrode far quicker when exposed to cold outside air, than if covered with coolant (which usually includes corrosion inhibitors.)

They used to make something called a dip stick heater. I haven't seen one for a long time. They also make a magnetic block heater I think. I would check into either of those options just to be safe.

They also make one that goes into the block, just like a freeze plug. And somebody else makes a really neat version that goes right in the radiator hose and pumps warmed coolant with a little pump.
The fact is, none of any of the suplemental pre-heaters mentioned here tonight will do anything more than give you false hope... if... if... if you don't have enough of the proper mix coolant, filling the system. Period.

Capt Rich - I didn't think that straight anti freeze was a good idea either. The proper mix is best - or buy the premixed stuff.