First thing I would be sure of is that this is the dipstick original to the car. Don’t know exactly why your dipstick shows so differently based on the way you “stick it in”. I think I would use some middle point between the two readings as the oil level. Certainly by following the refill recommendations in the BOOK you won’t be hurting anything. The dipstick in my ’55 with a 292 isn’t the most accurate thing either.