Just installed a new (aftermarket) fuel tank, inlet tube and fuel cap (also aftermarket) on my '68 project and darn if the SS cap is about 15-20 degrees from level. I removed the inlet tube and tried to readjust the angle of it in to the tank but still the the cap is 15 degrees short of level. Kind of embarrassing. Any Ideas? Is the obscenely expensive GM cap indexed differently?

My repro SS cap was a little bit off. I put the gas tank end in a bench vise, grabbed the with both hands, and twisted real hard to re-index it. Then I bought a NOS GM filler tube to replace my worn-out original and had to turn it back a little bit by the same method. I don't know if you can do the same to original SS caps.

Has been discussed here several times, seems to be fairly common.

Here is one thread:

http://www.camaros.net/forums/showthread.php?t=77504

Thanks, I'll try those suggestions.