Converting an autochoke carburetor to a manual choke carburetor is tricky; and even more so to operate from now on.
First, you have to make absolutely certain that the fast idle cam still functions normally.
Second, you MUST adjust the manunal choke such that it NEVER completely closes! This is important. Most manual choke carbs have a poppet relief valve in the choke plate whereas auto choke carburetors do not. The vacuum will partially open the choke immediately on an auto choke, and you no longer have this feature.
If you have the above correct, start the engine, and warm to normal operating temperature. NOW is the time to set the idle (hot, not cold). If you did the conversion correctly, the fast idle cam will take care of the cold idle for you.
Finally, each time you go to pull the choke cable when the engine is turned off, it is imperative that you depress the footfeed at least halfway. This is necessary to disengage the choke lockout found on auto choke carburetors.
Really of more importance, is what engine is the donor engine for the carburetor? When migrating an O.E. carburetor from one engine to another, best results will be found if the donor engine is within 3 percent displacement of the donee engine. Since you have a 305, 3 percent is approximately 9. Thus, you should be able to adapt a carburetor from an engine within the range of 296 to 314 CID.
305 Stromberg carburetors are not that difficult to find.
Jon.
