Miss and carb tuning troubleshooting

Hey all, I have been reading thread after thread trying to narrow down some of the issues I have and took in a bit too much information and need some help to get me in the right direction before I start tearing it apart this weekend so I'll lay out the problems at hand.

73 Scamp specs:
-318
-eddy performer intake
-eddy 1406 carb
-long tube headers
-2.5 in exhaust
-Trailbeast's HEI and distrubutor
-NGK BKR6E spark plugs
-possibly some unknown rv cam, has a slight lope at idle
-initial distributor timing set at 15 btdc, total 35 @2500rpm, vac advance can set at +15

So I'll start out with the miss, at idle, part throttle acceleration, and wot there is no apparent miss at all, but at cruise in town/freeway or free revving the motor up past idle at a constant rpm, there is an audible "pop" coming out of the passenger side exhaust. Has anyone experienced a similar issue? Leaking intake manifold gasket? Burnt valve? Not sure.

*Edit* Also, if i get on it pretty hard, and let off the throttle to coast, the back firing becomes more apparent, if that helps at all.

And the other thing I am dealing with is how the carb is running. Currently set at 1 stage richer in cruise (to see if that would get rid of the miss) and using the silver springs, going to go lower to possibly see if helps the issue. I have been monitoring on my wideband this past week on my commute to work, idle afr is at about 15-16, cruising about the same under 35 mph, but as soon as the rpm's go a bit higher cruising at 60-65 mph, afr is at about 14-14.5 (which is what I want below 35 haha). Springs might have something to do with this, thinking not having enough manifold vacuum at 2500 rpm cruising on the freeway to keep the rods down? I was under the impression the afr shouldn't change much if the rods are down at cruise even at a higher rpm, if that's the case, change the rods cruise mode one stage more rich and softer spring to balance it out no? And the final issue I have is lightly tipping into the throttle to accelerate, afr is around 14's, but any sort of not so light movement to get up to speed/half throttle/wot the carb just dumps fuel, afr hitting 10-11. Stock fuel pump (fairly new replacement) pressure sending too much gas to the carb? Float adjustment? I don't know, but will reset everything this weekend. Every post I have seen about issues with this carb seem to be off idle stumble or lean bog conditions when flooring it at speed, I have the complete opposite of this issue and she gets up an will spin the tires off as soon as I peg the gas.

So those are my woes, I have on the way a rebuild kit for the eddy, a fuel pressure regulator to limit the fuel to carb to about 5 psi as per spec, 1/2" wood carb spacer because sometimes is takes a sec to start when hot, (**** california gas evaporates too easily). I gave my input on the things that I think might work and what the issues could be and you guys will probably school me about HAH! Hopefully I'll get something out of it, I get the basic concepts and all and am having a fun time learning, tuning, and seeing what others have done in their experience.