Need help, advice with my 318 build

I have done a very similar build on a Ford small block with even less cam duration, but with a lot of lift. I would suggest going to 1.6 rocker ratios; you can keep duration low but get more breathing with that to make up for it. The more you can open up the ports, then better you will like the top end RPM performance. You can use a thicker head gasket to make the SCR and DCR lower, but I have run 10:1 SCR with quench and low duration, and it was perfectly OK with premium gasoline.

For your use, I would stay with the duration in the 250's range but I would prefer a wider LSA for the mileage and torque, at least 112 degrees. I would be looking at the Lunati Voodoo 10200700. The Crane 'hydraulic economy' cams in the 70's made for good torque and mileage had a 114 degree LSA.

I like what you are doing there and the fact that you have your priorities clearly defined.