Painted my 53 in my garage with single stage urethane two years ago,
Same problem with you with space, first the cab, day later the four fenders, couple days later the bed pieces and grill and tail gate-then hood the last. Turned out great, paint doesn't know what time it is.
On paints that come reduced already like summit brand, it will take two gallons, at least. Make sure you get some paint cans and mix it really good between gallons, the only advice I have.
Steve

PS thanks for the links Tim, some good reads there.

Last edited by sstock; 08/01/2019 12:43 PM.
1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration