HF air compressor

About spray guns. Technically, and I say technically, you are supposed to be able to change air caps and fluid cap on some guns to be able to use lower CFM's. I tried with a Devilbiss gun, but didn't seem to match up. I followed the recommendation in the book.....

I am a paint duffer! I just use cheap guns!!! I have had good success with HVLP guns from TCP Global, Summit, etc. Pint really bothers me, I love to do it but, I really need an air suit, been never been on my $ plate. Hopefully I will paint lower area of my Volare, and maybe paint the 71 Duster less I sell it off.
Back in 90's I rebuilt quite a few Mopars and had a good young guy that did most my bodywork. He used some sorta square box that did the air, I never new exactly what it was. He laid down flawlwss work. I just did some work with the old siphon gun on drivers I would sell/trade..