I posted some time back (oct 2018) regarding a big backfire through the exhaust on my (then) recently acquired ‘82 C10 with integrated head 250-6. Motor had mystery carb on what looked to be a home made adaptor plate. Rusty Nail immediately called “vacuum leak” - it was. DBarre made me a deal on a correct carb - worked. Got around to working on the truck this weekend. This “fix” should keep it on the road until the new motor swap is ready... but that was/is another post. Thanks to all who participated in that long ago post.