I recently had a LS1/T56 put into my 87. I am going to finish up the the odds and ends myself, radiator, gauges, n fuel system. For the fuel system I chose to go with Aeromotive A1000, with corresponding regulator and filters, and steel braided lines from front to back. I had the stock tank modified with a drop sump in the rear to accept all the AN lines. The drop sump is AN -06, my plan was to run both -06 to a Y Block to make it -10 to the fuel pump(filters on both sides) run to FAST fuel rails and to the regulator and back to a return line in the tank. My main question is if that will work or if I'm missing something. And also on an 87 ELCO where would I want to mount the A1000. I know as close and low to the tank as possible but if anyone has done anything close to this pics would be a great deal of help. Thanks for all the help.

Here is a photo of my tank with a sump. http://s329.photobucket.com/albums/l374/charlestillema/fuel%20tank

You should mount your pump as close to the tank as possible. What size filters do you have? I recommend 100 mic before the pump.
Your setup sound like a winner.

Drivers side just fwd of rear wheel on inner frame rail along with filter?

Thats a lot of coin in a fuel system. Are you running forced induction or something? I think you'd be money ahead trying to find a TBI sending unit and adding a Walbro pump to it. Then you could just fab up some fuel lines along the frame rail. You could run a half inch feed line and still feed a warmed over LS1.