Just some added info and opinion. Some hot rods may
look lightweight, but getting actual wheel weights can be surprising. For example, my avatar roadster weighs 2550 lbs. with a 1/2 tank of fuel, top and hood, but add 2 people, luggage, cooler, full fuel etc. and it's at +/- 3000 lbs. and no longer a lightweight.
I agree that adding Bendix drum brakes on the front and keeping (or adding) Lockheeds on the rear is a worthwhile upgrade and should provide good braking. A
better upgrade would be adding Bendix on the rears also, especially factoring in cost and replacement part availability. This would really compliment change to a dual master cylinder, as the rear-only Bendix will provide
much better performance during a front system failure than the non-servo Lockheed. (A dual master conversion is the
first change I would make, regardless of brake style.

)
Keep in mind that adding a power assist that's been suggested doesn't improve actual braking, it just requires less pedal effort.
