My carburetor needs replaced! the "BB" in the discharge chamber is stuck. Carb. is manual choke. I have a guy willing to sell me a Rochester B,with an automatic choke. the price is right,but does anyone have experience installing one on a 235/261,with Fenton's? Is it possible to convert the auto. choke carb. to manual,without compromising the integrity of the linkage,(vacuum leak)? any tips/ideas are APPRECIATED!! THANKS!!