this is a great question, and i hope you get a lot of responses from others who have done this conversion. I've seen some pretty excellent installs.
I had started on baffling and sumping the stock 16 gallon tank and adding an intank fuel pump setup, but decided the 16 gallon tank was too small for what i wanted. There is a thread on here somewhere with pictures of what i was doing.
After some long time thinking and searching, here's the conclusions i came to (right, wrong, or just anal :shrug: ):
1). Best not to go below 1/4 tank on an efi car because the lower the fuel level, the warmer the fuel and the more aeriated the fuel becomes, the hotter the pump runs (leading to pre-mature failures, and fluctuating stoich).
2). That leaves about 12 usable gallons in a stock tank, which is about 240 miles cruising range. Which seems a bit short for touring, to me.
3). I
really like the idea of keeping the pump in the tank. It's quiet, cool, and out of the way. No catch tanks, minimal connections, and a very tidy appearance.
4). No fuel lines in the trunk! The thought of fuel lines in the trunk scares the heck out of me.
5). 22 gallon tank sits up too high to put a flat plate over the trunk floor.
So based on that criteria, i bought a '69 tank (20 gallons), allows a flat plate across the trunk floor), and a tanks, inc fuel pump kit. Optimally this would have been mounted in the left rear corner with the tray facing forward. My arms are too short to have been able to hook up the lines inside the front of the tank, so i opted for the left front corner, with the tray facing the left side.
http://i104.photobucket.com/albums/m184/66runt/img_1699.jpg
i ran a 3/8" hose from the pump to the -an 8 bulkhead, and then 1/2" hose to the filter and engine. For the return, i am using the stock '69 sender, and 3/8" hose. I did not want the hot return fuel to go back into the pump tray, and staying above 1/4 tank there won't be a starvation issue.
The capped off bulkhead is for a second pump, should i end up going to 60# injectors and more boost. I didn't want to have to mess with drilling or welding on a "used" fuel tank down the road.
http://i104.photobucket.com/albums/m184/66runt/img_1697.jpg
i decided not to run the fuel lines down the tunnel, like stock, due to exhaust pipe heat, and incase of a catastrophic clutch or driveline failure (just a bit nervous of the prospect of a flame thrower cotterizing the area of leg that used to have an ankle attached :loco: ). So i ran them down the frame (and subframe) rail, and up into the right side behind the shock tower. Still have to finish installing the nut-serts for the clamps. I went through the tunnel brace to keep things up and tight, and away from the header. Going from this support into the engine compartment the hoses will be inside of heat shield tubes.
http://i104.photobucket.com/albums/m184/66runt/img_1698.jpg