I got a set of carbs in a box when I recently bought my '81 GL500I. I have been tinkering with them, but got to wondering just what bike the carbs were originally for and if they will fit on my '81. On one of the carbs, just under the letters VB is stamped 29A. Seems like there was a post with ID information but I couldn't find it. Also, wasn't there a post that described the differences between the various carbs? Thanks.