[micky69396]

Change rear and trans to synthetic gear lube and dont worry about it. I would make sure the car is up to temp for sure or you are doing more harm then good running them a little. I would suggest once a year on the oil change, even then its probably still good. I have a employee who works for a oil testing facility as his real job, and there are a lot of heavy testing they do. Believe me sitting in muscle cars is not a problem.