i gallon will do two coats on the floor not including the tailgate. i would get two gallons and do that route if i were to do it all over again. one day i am going to put some more on ym floorpan since it adheres to itself.
just get a gallon and your set, just get a paint brush and slosh it around there, worked great for me!
it basically settles itself, so dont waste the extra money on the kit....
but mines already peeling btw after 6 months of BARELY any hardcore use
I used durabrak on my tailgate and it seems to me holding up a TON better than the herculiner brand name
Hurculiner works pretty decent, if you properly prep everything. I've had Hurc. on the '78 since July and drug stuff all about the vehicle. The only spot that peeled was an unsanded spot the size of a quater and only came up because of bare metal slider digging into the bed.
I also plan on using this stuff for my F150's bed once I get bored enough to do so.
Durabak, however is rumored to be stronger and has pretty colors, so it's another option I may use.