I think you will find that when you lay the 4 spd hump onto the new floor pan, it won't fit but in one place. Trace around it with a sharpie, and step in enough for good overlap and cut the hole. I will be adding one to my 70 Duster that was a 3 on the tree, and that is my plan. I'm seriously thing of using Fusor panel bond to hold it, and then just weld up the screw holes needed to hold it down during the bonding process.