96c1500FullRebuild
Newbie
It needs to be tuned. With that cam you're running way lean, hence the lean popping. Your timing is probably way off too. If you don't want to wait for the 0411 swap, go to Black Bear Performance, they tune "black boxes" all the time. 10" of vacuum is low, perhaps a vacuum leak???
http://blackbearperformance.com/
I didn't know they tuned these. I contacted them awhile back about the 0411 swap. I will reach out about a possible start tune.
The previous build I had this motor in had the same vacuum so I don't think there is a vacuum leak. I sprayed starter fluid all over all vacuum connections when I first fired it up running like this with the same theory to no idle reaction.