I wouldn't use a stock mag intake, personally...the 2 piece construction (open plenum bottom with a gasketed base plate) probably won't hold up to much boost. at the very least you'd want to use the hughes bottom plate, which is relatively thick aluminum vs. the stock lightweight sheet metal. I'd probably just buck up and get an M1 single plane
plumbing, you're probably better off using an LS1/3G hemi/ford 4.6/5.4 type of throttle body on an elbow vs. a stock magnum one.
stock magnum dizzy is essentially just a hall effects trigger (no mech or vac advance built in), the computer controls all advance function....you should be able to use it for timing control