Originally Posted by dmjlambert (Post 8367761)

How does somebody know what type of hump to order a mat for? When I was buying my carpet, I ordered it from Classic Industries, and the choices included low hump and high hump TH400. Since I have a TH400 I thought that means I need the high hump TH400 choice so I ordered it. There was enough room for me to add a 2x12 board under the carpet at the hump location, so I guess I got the wrong carpet. I like it anyway and now it appears I have a high hump with the board build-up. Are there 3 different hump heights with a 3 on the tree transmission and TH400 automatic are different or just two different heights in these trucks? When I wear out this carpet I think I will change to one of those vinyl mats like Bruce88 put in.

Originally Posted by Stocker (Post 8367677)

Found it, I think, though it says 'under carpet'. Might want to contact them & ask just to be sure but it sounds like the same stuff. GMC Pauls p/n 132823, $50.

"Front under carpet Factory style soundproof set made of original style tar-like material to deaden sound and absorb moisture to prevent rusting. Includes the white polystyrene top pad also. Exactly like original. This item has separate shipping charges as it ships oversized II Made in the USA"