Software Upgraded - Reset Your Password to Login
In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.
You can try to put a small hole it and use an extractor, however chances are that since the head broke off then the threads are corroded and might not budge. If you have an extractor set, go for it. Your looking to replace the line anyway, so you got nothing to lose. I'd spray some penetrating lube in the body and cover it. That might help break it up.
Cosmetic parts and interior parts are very interchangeable 89-93 but style may be different so there is a lot of potential for customizing to your own taste. There are basics such as the front bumper. The ones with a larger front inlet are GVR4, 93 LS bumper which deletes fog lights or JDM (possibly Galant GSX don't know). DOHC cars are most compatible in engine bay but the engine has several differences CR, cams, piston skirt oil squirters, injectors, throttle body, power steering pump which many think is an upgrade, and more. Honestly, a great many items are compatible but have subtle issues. If you see something you like on a different year/model but are not sure will fit, ask the board, probably someone will get back to you quickly.
I'm surprised nobody has mentioned the fact that the SOHC and DOHC in NA form have the exact same block. I'm sure the compressor would have the same mounting bracket. Thus, it is likely they would run the same compressor. Therefore all the lines would likely be the same across all 89-93 Galants, be they VR4, GSX, GS-R, GS, LS or base.
Dsm's have different compressors. The dsm ones are smaller and doesn't have a pressure switch hole like a vr4. I know because I made one work on mine but required having hybrid lines made and swegged together.
Given the shape of the car and the need for the lines to follow body lines, I don't think the main hard lines are the same. Now, if the length is sufficient, they may be able to be bent to fit, probably poorly. they are fairly flexible, but you don't want to kink of fatigue them as the aluminum can crack or split easily.
I may still have a compressor bracket around if you need one. I know I sold one a few years ago.