I'm looking for information about modifying the Rochester 4GC that came on the 1964 smallblock 300 for more cfm. Doug Roe's book has some information. Does anybody in the group have an old magazine article or perhaps a manual with info? I talked with Val Hedworth who preps these carbs for drag race motors. He tells me that they can be flowed to about 480-490 cfm on a good day. I'd like to give it a try. Thanks, Mark