Welcome to irv2 REF jr
Your asking for trouble wrapping your manifold to keep a cool floor. The old FORDs had big problems with cracked manifolds, broken bolts and cracked heads because of heat build up.
You would be better off placing a foil blanket kit in the dog house housing to reflect heat from surrounding floor surfaces.
The manifolds need as much hot air escaping as possible and make sure you have a good air-dam around radiator to force air thru you engine chamber.
Enjoy the forums and do post often.