It is always a good idea to store these cars with antifreeze in them. The cast iron will corrode quickly and let the seals move and they blow first time it comes up to temp. The area around the water jacket in some of these motors is .070 or less depending on core shift in casting. First put a pressure tester on the cooling system and see if it pushes AF into the chambers. Sniff tester(O2 sensor) on the open radiator cap with the motor running will find a leaking seal as well. If the car was designed to have a splitter and it is gone the low mounted oil cooler will not work. All the air is ducted with the splitter opening. Run the car with 200-220 water and never over 230 oil if you can. We run the factory 160 thermostat in all our cars.

Worst case you will need one cast iron and a seal kit if everything else was as advertised. If you have the motor cracked open replace the apex seal springs. Don't give up, it will be worth a little headache when you get it right.