A/C reached critical mass!

[engineer_gregh]

Stock setup on my big block. When the engine was out and rebuilt 4 years ago I replaced the expansion valve, eliminated the POA valve and installed a High Lo pressure switch, new receiver dryer, vacuumed and converted to 134a. Its always been ok but not great. Its been working for the past three years but cycled continuously at anything above idle. I decided that I would adjust the pressure switch. I upped the idle in park to try and duplicate the cycling; I'm guessing the head pressure reached a point that literally blew the manifold line right off the back of the compressor. I'm not sure why the A/C didn't cycle in park like it would with the vehicle moving? I'm open for opinions on the cycling and if I should just rip out the factory setup and go with vintage air? I don't even know if I can just bolt the hose back on the back of the compressor? I think it (hose with the manifold) is held on by a single bolt in the center but I've not found the bolt since the explosion.