Brand new to Thermoquads- a few questions I need help with

Thank you much for the input - this is a truly useful post. I have indeed found a 6139 carb to use instead of my 9103 so I'm listening to the chorus of "I've bought the wrong carb to work with"- which is how I usually start off on these things.....:-). Do you have a preference for rebuild kits that will have the x shaped gasket?