I bought this on this forum on good faith from a guy who sold it as a mustang carb - C6PF-H carburetor, - as the 289 runs poorly with it, I subsequently find out it is actually a factory replacement carburetor for a C6OF-H. This carburetor is intended for a 1966 Fairlane GT with a 390 GT engine and a 4 speed. It is also a california emmissions carburetor hence the 1.08 venturi. I could have it reworked but am told it is relatively unique and rare and would be a shame to do so. Anyone looking to trade for a standard 289 4100?