Bruce, it seems to happen in 2nd or 3rd gear about 23 to 2600 rpm when you step into the foot feed a little too fast. If I knew how to do it I would make the accelerator pump come in a little harder just off idle or put bigger pump nozzles in. If it was a Holley or a Quadrajet I would know how to do it. It's not real bad just kind of a hiccup. Yeah I do have the old Panchitos, Pat liked them because he said they cooled really well. It dynoed right at 150. It was really snappy until I changed the gears. That was when I found out my trans was a stock 4.12/.89 not the 3.88 I paid for. No wonder it was so quick. I did get the $450 refunded, even after two years which I thought was pretty stand up.