I purchased a fuel pump sp227h assembly that crossed over from Fords part # 98bp-9h307ab. The assembly will not fit flush with the fuel tank to get the metal ring back on. The new assembly is hitting the bottom of the fuel tub making the assembly to raise up on one side or the other. I have tried many different things to try to get the ring back on but the ring is sitting higher on one side or the other. The old assembly fits flush, but the new assembly I having problems with, Anyone have any suggestions? Thanks for your help,