Gas tank installation 69 cuda fastback

I bought a 69 cuda where the fuel tank and neck had been removed by a previous owner. I got the replacement tank in with great difficulty (had to bend the flanged ends for clearance) and now i cannot come close to inserting the fuel neck back in. The service manual says i can rotate the neck 180 degrees, insert it in several inches, and rotate it and withdraw it. That doesnt seem to work. I cannot get the filler neck close to going into the tank before wedging against the trunk brace or quarter panel. Any help out there?:(