Drop ????

[enigma]

I have been researching on here on 3/5 drops. But my question is, what is the best way to drop a 67 with fuel tank in back? For static drop that is. 3 inch springs and the weight of the fuel will drop it that couple inches or will HD 4 inch drop springs and one inch spacers be good? Also with the fuel tank in back will it be mandatory to c notch it? There has been debate on the c notch being not needed until being 6 inch or more but does that account for the extra 200 pounds being already in the rear of the truck? Okay I think that matches my four question marks lol. Thanks Baron