For a gasket I'd match to type of manifold. For any carb running off road a fuel regulator will make it better off road. Like it is about a necessity... and I don't run one. But I haven't been doing much where it matters in years.
Q-Jets causing fires? Had to be more to it. I can't believe a truck could run at all with a float stuck that bad. It couldn't have been running right. A fuel regulator could help that as well.
A friend and fellow member has been running his '69 Blazer off road in "obstacle" races for many year on a carb using a regulator, and he wins. He has made many changes to suspension and all over, but still runs a carb. This type of racing puts the vehicle through it all. Basically romping as hard as you can do on trails through the woods, hill climb (after going down just as steep and far), all out wide open, cutting new path over trees, and all