I didn't know you could check the oil levels from any other point on the motor, other than the dip stick tube that resides in the oil pan. So what you are saying is that if I buy a front sump oil pan, without a dip stick tube I can check the oil levels from the timing case cover, how so?
Some older smallblock timing covers had a dipstick in them. Most of them have the boss there on the passenger side (left side if you're looking at the front of the engine). You can get an aftermarket dipstick and tube and drill your own hole in th cover.
Ditto, Advance and Autozone both stock chromed small block dipstick tubes and sticks that are perfect. Got one on my 331. Drilled the hole thru the timing cover myself.
The timing cover dipstick is why you find all sorts of front sump pans without provisions for a dipstick.