The 1" quick couplers in the maple supply catologs will accept a piece of
1/2" black tubing inside. By doing this you can pump a plastic barrel out.
One year I hauled sap from 50 taps with two 55 gallon barrells in the back of a Dodge Caravan. My truck at that time was not road worthy even with AG plates on it. By using the 1/2" black pipe I could empty the barrlles out completly that were laid on the side in back of the van.
30x8 Leader revolution, wood fired blower, steamaway/hood. 903 taps all but 54 on pipeline and 3 vacuum systems. Hauling sap this year with a 99 F350 7.3 diesel dump and of course back up is the Honda 450 and trailer.