I plan on using an oil pan from a truck on a 292 that will go in a Model A and I don't have the dipstick or the dipstick tube. I have mocked up a tube and a stick but don't know where to mark the "full line". I guess I could put 4.5 quarts of oil in and mark the full line at that point but the front of this pan is modified a little and that may change this level a little bit. The other thing I got to thinking about is, are the truck pans 5 qt or 6qt? 
From what I understand, there two different truck pans, one heavy duty truck and a pick-up pan. Both of these pans are rear sump but the pick-up pan has two "steps" before the slope to the front and the H.D. pan has just one. I have the H.D. pan as mine has just the one step before the slope. Is this H.D. pan a 6 qt pan?
So, I'm thinking the best way to do this is to find out how high the oil should be below the pan mounting surface of the block and mark the dipstick at that point. Does anyone know how far from the block the oil level should be?