I'm in the process of converting my '66. Which kit did you get? I'm using the Aeromotive Phantom in-tank fuel pump and a FiTech EFI throttle body. The wiring was pretty straight forward with this kit because the throttle body includes the fuel pressure regular, fuel pump relay and ECU. Saying that, I can't get it to start. I think it's an ignition issue. Not sure if it's related to the FiTech. I'm still trouble shooting. I did go with the option where the FiTech controls the ignition timing instead of leaving the MSD Probillet and 6A alone. Made it more complicated then needed it to be I guess. I had to lock out the distributor which isn't a difficult process and the wiring is straight forward. Not saying all this to frighten you. I'm sure it's something simple that I can't see at the moment. I replaced the original fuel line from the tank to the engine. Used all hard line, the nickel/copper stuff because it is easy to work with. You may need a return line depending on your kit. A followed the original path for the supply line and went down to opposite side (passenger) for the return line. Not much room to hide the lines with the unibody. I'm not sure how your
fuel tank is setup in your 69. The 66 is installed in such a way that I had to cut a hole in the truck above the tank to make room for the fuel pump mounting flange. I was thinking of putting in a spacer to lower the tank but I didn't think the filler tube would line up. Anyway, these are things that I came up with. Not sure if any of these while apply to you.