2 carburetors made for a much smaller engine are going to be your only real hope here, Dad. I'll leave it for others to tell what carburetors have worked for them, but 2 Rochester Bs are in my opinion like taking a butter knife to a gunfight. If you didn't straighten the castings on the Rochesters, they're extremely likely to run very rich and flood all the time. And even if you did straighten them, the Rochester B by nature is...well, I'll stop here. I was taught to try to say nice things whenever possible, so let me end with this: Rochester Bs are carburetors. They were made by GM and possibly designed by Nikita Khrushchev after too much vodka. And remarkably thousands of them are still in use today.
