Hello. I have a few carbs. I looked the numbers up on Holley.com. All the numbers make sense. But what confuses me is on each carb there is a 4 digit part number, followed by a hyphen and then another number. The Holley site has the carbs listed as having 4 digit part numbers followed by a letter. The part numbers are as follows: 4779-9 4777-7 4779-9 4778-8 4780-7 80770-1 Any tips? Thanx so much.
I read some where a while back that the number after the dash is the number of mods that the factory made to that particular series.....as it was developed.....
Here's a nice list from Mortec- http://www.mortec.com/carbs.htm It looks as though the dash represents how the carb was set up from the factory- ie- jet sizes, power valves, etc as Doc eluded to.