Suitable Vapor / Over fill valve for retrofit

Thanks!!! I have confirmation of what to do! The 68 satellite does not have a vent tube on the filler neck. It has two short flared vent tubes coming out of the tank. Originally, both tank tubes connect via hose to two lines that vent to open air. One tube goes up and back down and the other goes up in the trunk and back down into the frame rail.
In my retrofit it teed the connections from the tank into one and connected to the line that went to canister along frame next to fuel line. But now I’ll put the gm part in between them after my tee. Makes sense. Thanks again!