When Bubba327 changed out his heater core for the larger core he had to open up his upper lid the accomidate the larger core, as shown in the pic above....my upper section is already larger/factory but has a notch in it for a block off plate, I`m assumming that this would be a later design as to cut costs one box fits all...? I ended up with a smaller core only because I could`nt find a larger core locally, made a quick plate from alumimun. Anybody have pics as to how the factory hung the core in the box.....?