I'm trying to determine the actual capacity of the Diesel
tank on my 1979 Gulfstar
37 aft cockpit
. I've gotten conflicting reports from different sources, so I am hoping there are some owners out there who know what the actual capacity is supposed to be. THe tank is the orginal that is an integral fiberglass keel
Some sources say 30 gal, some say 50....I know it will hold 30, as I have put that much into it, but I don't know how much was in the tank when I bought it, so short of running it dry, don't know how to figure out the capacity. Any ideas?