The holly/weber rebuilts that Langdon has for sale are ok as a base product to jet to your particular application. There are a couple of good places to go on the web to purchase main jets, idle jets and air correction jets, and emulsion tubes. I'm in the process now of jetting one for my 244 engine. I do know that doing the calculation for emulsion tubes I need an F6 in the primary and F50 secondary. The F6 will aid in drivability.
