Just bought a 1985 SR5 pickup on craigslist and in the process of getting it running right. On the way home I noticed it had a squeaky belt. Upon further investigation the squeaky belt is because the alternator is loose. I discovered that the bolt that holds the upper alternator bracket to the block is missing. I can't seem to find this bolt on any parts website. If anyone knows the dimensions of this bolt I can probably pick it up from NAPA. Any help would be much appreciated.

Also any advice on how to replace this bolt? Looks like I might have to remove the radiator.