I will be getting a 1972 Ford Gran Torino Sport in the next couple of weeks. The car is a super straight, 140K mile all origninal. I need to put the car into storage for the next couple of years until I have time to do the cosmetic restoration. The drivetrain in the car runs literally like new. The engine has great compression, no blow-by, and virtually no oil consumption. What oil would best be used for this sort of storage? I was thinking something like a HD fleet oil might be best for this sort of application? Perhaps a synthetic would be better? The car has been run on Castrol dino 10W40 for at least the last 10 years a religious oil change schedule (all documented). Any suggestions on what oil would be my best choice? If I switch oils now, is there a possiblity of an additives clash from the remaining Castrol 10W40? I don't want to run synthetic either if it will cause the engine to leak. I suspect that the 30+ year old engine gaskets may not like synthetic, and the car does not leak oil now. Any advice appreciated.