Backfiring issue

I had been doing diagnostics, and even relenting and taking it to the shops. When I realized after I got it back from one of the shops, and they told me the carb was bad. Took apart the whole ignition system and realized the distributor cap was in bad shape. Not sure where the thought that I was just throwing money away? The compression is not bad, I checked it finally.
Up until the FIRST SENTENCE in the above post, you said nothing about anything except parts replacement, so how was anyone supposed to know you diagnosed anything? A crystal ball? As for the throwing money away comment, it was a general statement about what the lack of diagnosis will get you. Have you made any progress? I have a couple of things you might try if not.