My cousin has an original 64 SS 4-spd that the floors need to be replaced. He has a solid four door he picked up to fix some cancer spots on the two door, he wants to know if the four door floor pan will work in the two door. I checked some vendors and they made no mention of two or four door just 64-67.

Yes, The 4 Door Floorpan will work work in the SS. Floorpans are the same on 2 Door and 4 Door Chevelles.