318 2bbl won't idle without choke

Here we are running with a clear carb top I made, and a makeshift "choke". Vacuum gauge with the "choke" read about 5, and yesterday read about 15 when we were running it with the choke off.

I'm beginning to suspect the timing. My timing gun broke, but looking at it statically the points haven't even started to open until well after TDC - at least 10* if not 15 or more. MY research has alerted me to the nylon timing gear these engines used, and since I'm sure mine is original I'm inclined to replace it and the harmonic balancer (and the water pump while I'm there) before going much further.