Vintage Cars: Car wont start, positive cable, negative battery

Question
Hi Ron. I'm replying about my 250C. A bit over a year ago I replaced the negative battery to the cable cause that one itself was loose and too old so what you say makes sense for me to look into the positive cable. Now if the car is sucking too much air what may I do?. Lastly do you maybe have used parts for sale? I'll chance an autoshop for the fuel pump flange.                                           P.S. I'm looking for where I'm supposed to rate your reply but can't find it. Thank you for taking time to help me with my problem. Al

Answer
what i mean by that is to look at all the rubber connections and gaskets from the carb and on the intake mainfold, fuel pump , looking for signs of dis repair , or leaks. I do not have any 250C used parts right now but have some contacts if you get stuck and cant find something
Not sure about how to rate, I may be able to send a link
Ron