The tanks on fordors are mounted under the exterior cowl and are attached and removed differently than other 28-29 models. Basically, after all the peripherals are removed or disconnected, there's a row of bolts to the lower firewall, bolts and clamps on each side to the cowl panels and bolts across the top behind the dash panel. Then the tank is lifted up and out towards the front. Pretty much covered in this old thread, good luck:
http://www.fordbarn.com/forum/showthread.php?t=105080