The LD4B is a great intake. It's the 318 version of the LD340 and has great street manors.
When we bought the oldest boy's Valiant with a 318, it had a performer intake and 4 bbl carb. We installed an LD4B and Edelbrock carb, and it ran great. Strong off the line with no bogs. It put the edelbrock performer to shame.
I would run the LD4B vs the air gap even with the slight port mis match, I think it will be a good street intake on a 360....