Cylinder piston area is pi x r^2, that x h is volume. R on a 2" cylinder is 1". But retract side you subtract out the crosssectional area of the rod, which is probably 1.125 or so diameter.
Anyway, the 19ci orbital will be huge for that. I have a 2.75 DE cylinder with a 1.5 rod and a 9.7ci valve for about 3.5 turns lock to lock.
The burb pump is probably a Saginaw P pump, good in stock form for about 3.5-5gpm. A gallon is 231ci, a decent steering speed is about 1 revolution per second, you'll probably have a hard time getting faster than 2 rev/second in anything, if you can get lock to lock in under 2 seconds I'm impressed...
So at that, pi r squared h on a 2" cylinder is about 25ci, your pump moves about 13.5ci/second, so if you look at it as pump limited, bigger than 13.5ci in the valve is of little benefit. If you look at it in terms of "normal-ish" lock to lock count, most small performance cars run in the 2-2.5 turns range, full-size trucks in the 3.5-4 range, for 3ish turns you'd want 25/3 or about 8.3something on the extend side. Retract side drops about a third of your volume, so increases steering speed, and reduces power, by about that ratio.
How big a tire, how much scrub, and how heavy a rig? That all plays into sizing this right.
apparently hauling through the desert was 2 hands death gripped on the wheel.
