thoughts on the edelbrock sp2p manifold

planning on running a (580 cfm total) dual 2 bbl set up. this will need a strong vacuum signal to work well and from what my buddy says...i should run the sp2p manifold . he says i will get better mileage, more low end torque, and will have a power band from idle to 4000 rpm. i cruise it and usually never go fast

the car has 2.76:1 gears and a stock 1976 low compression 318 engine
late 60's a body