Theoretically yes with the right materials, but realistically 3d printing is too sensitive to safely and reliably print pressure vessels of any significant size without putting yourself in danger. Some plastics are going to have weak points between layers that could splint apart instantly and without warning, and other plastics that don't have that problem are often brittle and could throw large chunks. But pressure rated plastic pipe extrusions are fairly cheap (just be aware some are only rated for water pressure, not air pressure). And if you need something small and lightweight, pop bottles can hold up to 100 PSI. Tom Stanton's channel on youtube does a bunch of air powered RC planes and stuff using pop bottles to hold air.
Maybe external mounting brackets? Say for the ignition system or maybe a sight of some kind? I wouldn’t trust a 3D print for any of the high pressure stuff but I don’t actually know if that’s feasible. I’d love to find out I’m wrong.