So I have found this part, and it's 40$. Ugh. I'll be going to a junkyard hoping there is one somewhere. Most places list this as discontinued. Or I'll just get the thread size and buy an aftermarket pressure relief valve and stick that in there. Good news is at least this part is easy to get to.

Thanks both of you. Yeah it seems to be confirmed High Pressure Relief. Now finding it has been another issue. This car was retrofitted so maybe this High Press Valve is from a R12 Unit. The search begins.

Hello, I cannot identify this part. It is located approximately 1 foot past the orifice tube on the passengers side, just before getting to the radiator. It look like a High Pressure Valve but I cannot find any sort of replacement part for it or anything that looks the same. Hoping somebody can help...