I have to drop the gas tank in my 84 Z28 and replace the sending unit. Can anyone tell me the best way to drop the tank?

 

Yep, lower the rear end as far as it can go.
I also removed the exhaust out of the way too.

Also, have someone help you do it, since it's awkward to move around.

 

OK so how do I lower the rear end?

 

http://www.users.qwest.net/~nscamaro.../FuelPump1.pdf
http://www.users.qwest.net/~nscamaro.../FuelPump2.pdf
http://www.users.qwest.net/~nscamaro.../FuelPump3.pdf
http://www.users.qwest.net/~nscamaro.../FuelPump4.pdf
http://www.users.qwest.net/~nscamaro.../FuelPump5.pdf

 

Tank removal can be accomplished in a day if you have good luck with rusted bolts and nuts coming off without too much trouble. Getting the rear end down low enough(or removing it altogether) is the key to getting the tank neck down out of its hole. If you're dropping the tank, you'll want to replace it or have it professionally cleaned(mine had an inch of junk in the bottom of it even though it didn't leak)before putting it back in. Also, you probably have an in tank filter that needs to be replaced. And if you're dropping the tank anyway, you might consider urethane bushings, new shocks, cleaning up the bottom of the body, lots of image enhancing things can be done with the rear end out of the way. New tank at Autozone goes for about 160. I put a nine bolt with disc under mine when I pulled the tank.
Good luck, post some pics if you can.