Leaky rear seal in a 66 plymouth.?

hi, i have a leaky rear seal in my 66 fury 3 the motor is a 2001 dodge 360 crate motor, came Straight from factory motor has less than 500 miles, i was told that the seal is leaking do to not being driven and dried up. Is there any kind of stop leak that would be safe to put in that motor? i do not have the resources at this time to lift the motor and repair it at the moment. it only leeks like 2 or 3 drops after i turn car off. thank you.