HELP! rebuild timing problem

[Kman]

I have a 350 I just put together, all stock w/roller lifters electronic ignition. the thing will not stay running under 1500 rpm and about 15-20 degrees advance If I retard spark it pops out the carb. I rechecked valve adjustment and it was ok,rechecked plug wires ok I'm thinking the timing chain might have jumped a tooth

also the carb a rebuilt carter 4 barrel has fuel coming out of only one side,I took the top off and checked for something clogged but every thing is clear

My question is is the carb problem related to a timing problem or am I missing somthing else before I tear timing cover off to check it? sorry to be so long but this is driving me crazy

any help would be great, thanks
Kman