Joe, A quick look in the 1929-57 Chevy Master Parts book shows at least 3 different U-shaped generator mounts for the 1955 1st Series trucks. There were apparently 3 different generators (30, 45 and 55 amp units) and each used a different bracket.
One bracket listed with an Overall Length of 7-1/8”. Another listed as 8-1/4” Overall Length. A third only listed by “stamped” part number “3703618”.
It’s very possible over the years your bracket may have come from something else, or is mismatched to the generator currently installed. It would help knowing which generator and bracket you have to see if we can help with the alignment issue.
On another possible theory, some brackets can be flipped from end to end so it bolts to the original mounts on the block, but moves the generator out if proper pulley alignment.
Please provide more info and some pictures so we can try and help figure it out. 😉
