Not from the factory. If you were to take a closer look at the engine you are refering to, you would probably find that it was a 59-62 replacement block with the '58 top end installed. This would have had the larger oil grooves in the rocker arms and would have allowed more oil to the top end, because they opened up the restriction in the block passages for '59. The bolt (and the plug) was then added by the jobber that swapped out the short block for the purpose of restoring the restriction as would be found with the earlier blocks. I have just went through all of this under another post by "hellfish". The bolt is only used when using '58 or earlier rockers on a 59-62 block.
Again, look at a 58-62 manual, it shows how it was supposed to work...
