If I understand correctly you have A Polly 318 with a 360 LA 2bbl. Intake manifold on it ? That doesnt fit....
and befor the head work done this ran ? well ?
Or did you get the head work done to make the intake work?
The 318 heads 2bbl. Will not match up smoothly at all with a 360 2bbl
The size diffence is too great.
there is a reson they have both 318 ..360...specific maifolds 2bbl. 4bbl.
and this holly 2bbl carb is not calibrated for your 318 ...if it came on that 360 manifold off a 360 engine .
you have to be more accurate in your part specific combo..
I have tryed these combos years ago beleve you..me..
You may have a maifold leak...at the heads let alone the ports dont match/aline.
the carb if off a running 360 will not drop on a 318 without tunning...and if its the 2bbl. Holly I think it is tunning it will be next to imposible ..lack of tunning parts.

 

At one point it did run decent without missin or anything. I've been fighting electric issues ever since though. I don't know why someone put this odd combo in the car. Here's the cast #'s
My 1974 Charger SE Baby Blue White Top
VIN # = WP29K4A170230
Block Cast # Driver Side = 2532630
Head #'s = 2843675
Manifold # = 3698437