I keep reading adds for Z's that have a electric fuel pump and the stock mechanical fuel pump. In my experience this is a tad bit overkill. Why would you want both. If I was going to install an electric pump near the gas tank, I would simply remove the mechanical one and block it off.

Anybody know of why you would want to have both?

I think it had to do with the fuel system problems that the Z's had, due to underhood heat, early on.

I eliminated the electric pump from mine, and its fine with just the mechanical. Stock L24 with new ZTherapy carbs. I just think mechanical pumps are more reliable.

Feeding the mechanical pump with a low psi electric pump made it easier to avoid vapor lock in the fuel lines on the late 72's/ 73 cars. The mechanical pump didn't have to work as hard.

Yeah in 73 when they had to use the dreaded flat top carbs with the float bowels that are internal, they had a major vapor lock problem. They added an electric pump so it wouldn't vapor lock. it didn't work. They then recalled the 73's and the dealer added silver heat insulation to the fuel lines. That didn't work either as it was not the problem. the carbs would get so hot they would boil the fuel out of the float bowels and they where very difficult to restart. Most owners swaped to early carbs (70-72)which perform much better. If you are using round top carbs all you need is the mechanical pump. My 73 has 72 carbs I do not use the factory fuel lines at all. I use a electric pump at the rear and braided steel AN lines mounted on the drivers side. I split off to each carb with a Y block and run a return line back to the tank. I have a rear mounted in line fuel filter and pressure regulator,very tiddy & it works great. I use a MSA fuel pump block of plate and don't have any stock hard lines on the frame rail and fire wall.

This is exactly what I wanted to know! Thanks again folks. As usual great info.

yeah I just started with mine but the mechanical fuel pump seems to be doing fine