What should the compression be on my dle 55 rear exhaust in PSI

Greater than 120 psi

I don't put much validity in compression testing on small gas engines. The problem is that static compression tests can vary so much between perfectly good, otherwise identical engines. I look at mechanical condition, how the ring(s), piston and cylinder look when inspected and how the engine actually runs to judge the condition of the engine. On our simple engines, a good visual inspection can tell you more about the engine than a variety of tools can. Certainly measurement tools have their place but they are no substitute for a good inspection. I also look for a bit more compression when the engine is cranked backwards than when cranked in the normal direction. Certainly if the engine in question has very soft compression when cranked, there is probably a problem that should be dealt with.