A spray gun only has its trigger pulled about half of the time when spraying a small object like a guitar. And the whole coat only takes a couple of minutes. These breaks allow the compressor to catch up. Also the tank serves as a reservior. So in reality you can use a much smaller compressor than you'd think. I have been using a little 2 hp, 5.5 cfm unit for 30 years and it has never failed to keep up with tools often rated up to 10 cfm.

A spray gun only has its trigger pulled about half of the time when spraying a small object like a guitar. And the whole coat only takes a couple of minutes. These breaks allow the compressor to catch up. Also the tank serves as a reservior. So in reality you can use a much smaller compressor than you'd think. I have been using a little 2 hp, 5.5 cfm unit for 30 years and it has never failed to keep up with tools often rated up to 10 cfm.

I can't find an accurate (and simple way) to convert the 2 to see if that compressor will fit the bill for that specific gun.

Does anyone know how to convert the 2 and determine if this compressor will work?

A compressor will deliver more air at the lower pressures used for HVLP conversion guns, but it's not linear due to a whole host of reasons. A 5.5 SCFM@90 psi rated compressor will likely deliver 25-30 percent more air at 40 psi, so perhaps 6.8-7.1 SCFM.

... I did just enough aerodynamics and viscous flow courses in college to understand just how little I know about what really happens inside a compressor or jet engine or rocket nozzle, and how often the real world surprises.