Alright so to resurect this thread, I have some info. I too used to have this same Murray Image. It was my first ever road bike and now I ride a full carbon Specialized Tarmac. We all start somewhere, so this Murray has a special place in my heart. While it's true they don't hold much value, are heavy and low quality, you can still get creative with it.

It has a standard BSA 24tpi 68mm bottom bracket shell so modern bottom brackets and cranks will work. The headset is old school BMX 1" threaded, so if you replaced the headset you are somewhat limited. You can, however, change out the fork with any standard 1" threaded fork if you wanted to. If you really wanted to, you could probably build up a 26lb road bike with modern components on this frame if you really sank money into it and tried, but it would have to just be for the challenge and/or kicks and giggles.