A holley 650 will give you less performance then a stock q-jet, so plan to get one.
Milage will probly be better too...if you can keep the pedal off the floor
Flow Masters should be called Flow Stoppers.
Dynomax's cost less and flow better. Sell the flow mstrs to a chevy/dodge guy.
And make sure you buy ignition wires for an "hei" distributor.
Wires for "points" are not made for that much voltage.
AC-Delco R45TSX(or equivalent brand) gapped at .060