So right now I'm in the middle of removing my engine and everything else in the engine bay to freshen up and clean it all. 77Z been sitting for 7 years. When I drained the gas tank there was about 6 or more gallons of old gas and some of the black gunky stuff I'm gonna assume is varnish.

Having that gas and gunk in there I'm guessing the tank, lines, pump, rail, injectors, and every other part of the fuel system has been at least a little gunked up and I'm wondering what is the best way to clean all that out?

Thanks!

Varnish is brown. I'm guessing the black gunk is like soot? If so, it's deteriorated rubber from your fuel lines. It gets recirculated through your fuel system and back through the return line to the tank, where it deposits as a fine film all over everything. The only thing that will remove it is mechanical action. I found a pressure washer very effective in blasting the stuff loose, although you won't be able to get every nook and cranny. I suspect whatever is deposited on the walls of your fuel lines is there to stay.

I'd replace each and every fuel line, including the vent hoses. The largest hose is about 5/8" and is hard to find, but you can get it at a tractor supply. Note: These are all FUEL lines. Don't use the heater hoses, or they will fall apart.

Good to know, so let's say I drop the gas tank, would it be ok to take it to the self serve car wash across the street, spray it full of degreaser and then powerwash it? Or will this possibly damage the tank's lining/leave bad residues?

I know there is recoating products for gas tanks which I'll probably use if I drop and clean the tank.

http://atlanticz.ca/zclub/techtips/fuel/gastank/index.htm

I always forget how endlessly useful that place is, thank you Blue.