[JLMounce]

I would bet it helped a little. My 580hp 465 with a slightly larger cam is doing better in town than you're getting on the highway, with a less efficient automatic behind it.

I provide fueling with a FiTech that controls timing as well.

A batch fire system like yours is never going to be a big winner in the fuel economy game, there's too much fuel wasted to that batch process and inefficient fuel burn due to liquid fuel puddling on the back of the intake valves. The additional timing is likely helping to light that off more efficiently though.