No power all of a sudden

[tino0217]

My 71 C10 350 sb, after finding a short from an after market tach installed for timing purposes led to changing my hei distributor, coil and module also found my radiator was shot so I replaced it. I went through the timing like I did before, 3 yrs ago, 12° advanced and it ran like a champ. While I was trying to figure out why I wasn't getting any power I found there was a intake leak so I replaced the gasket. Now with everything done hoping to fix any gitty-up set backs, I find myself back at square one. The engine sounds a lot more powerful with good compression better than it ever did but I can't get any power when I give it gas. I'm getting some slight backfiring in the exhaust and was able to take that down by adjusting the carb air-gas mixture. The only thing that I need to look at, as of now, is my automatic choke because it doesn't seem to be working the way it did after everything I've done. Could this be part of the problem? Any suggestions would be appreciated.