65 170 idles ok, starts ok, pops through carb

I couldnt get it running smooth with the old carburetor so I swapped it out and put it a new distributor while I was doing that. I believe when we did have it running a year ago with the old carb and distributor on it was running, but running rough, idling rough. But at that time was when I got the car and I just wanted to see if the engine ran. It had sat outside a shop for at least two years not running before I picked it up for free, no telling how long it had sat before it showed up at that shop. I think I did have it running with the old carb on there and I don't remember it popping, but I can't remember for sure. It's at another location so I don't get to work on it very much. Timing is a 5 BTC, specs for a 66 170, I did have it at 2.5 BTC and thought it was popping because of the timing so I bumped it up to 5 but didn't help. The idle is 550 RPM and it's a strong idle. I'm wondering if the valves have deposits on them. Should I run a strong vacuum hose fed intake cleaner through it? Oh yeah I just remembered we pulled #1 tonight to recheck TDC and the #1 plug was already black with some fuel on it.