Hmmmmm, 198 issues

I have a high elevation Dart with a 225. I'm the third owner and it lives at a similar elevation to you, 4800 feet. The guy I bought it from stored it in an airplane hanger, and maintained it like it was his second airplane. He tested compression every year and I have the log. At 53000 miles he tested it and got low 120's in psi all around. He lives slightly lower than me at about 4600 but the car swapped between here and Montana which may have been slightly higher. I think most of the tests were done here though. His tests a few years later were about ten points higher (an outlier), so I assume at least that test was done in a different place. Lowest and highest cylinders matched in both tests.

It was mentioned that your engine has a static c/r of 8.5 from the factory but I'm pretty sure all slants measure much lower from the factory. Mine burns about as much oil as yours, and while it is possible to be valve seals mine burns oil on very new seals (head was rebuilt with hardened valve seats not too long ago). Unless the car was equipped with a high altitude carburetor it is likely rich (I know mine is). Unsure what years or where those changes were made, but I know they did that with some cars in Colorado. Mine probably just washed the cylinders with a nice stream of rich gasoline its whole life.

The lowest psi my records show is 115, and he replaced the head with a burnt valve at 60. 90 sounds pretty awful.

Hope that helps,
Brandon