check the manifold choke system... spring and rod could get stuck inside assemby.
BTW it can take very long! thats why on laters models got the electric assistant control ( this si for BB, SBs got the same without ballast ):
http://www.ebay.com/itm/NOS-1974-76-most...44e&vxp=mtron a side note.... by the way you run the spark plug wires on driver side I guess you got the MP repro spark plug wire set. That's based on pre 72s setup... those are incorrect for 73 and lates B blocks
this is the correct set:
http://www.ebay.com/itm/360171097502?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649driver side wires are longer to reach the valve cover route. I got a set with that PN and prooved ( 3838000 is the PN on my 74 catalog ). Then from that, requested that lenght to customwires set ( firecore )
it looks you have a missed bracket thought, which bolts to the top front valve cover bolt.
I can give you measures if need, ALTHOUGH now, firecore set should have the measures to make them under request. I emailed directy with Lindsay and Rick about that