There are a lot of products out there like Dynamat,acoustic core,and products with lead to deaden sound. These are very expensive. I used a product from HD that was made from jute felt and a reflective thin Al foil on one side. It came in a roll and I bonded it with a contact adhesive (Weldwood). It greatly reduced the engine noise and heat. It was about 3/8 in thick and just bonded it over the existing insulation. I also repaired the seals surrounding the dog house and adjusted the clamps that hold it in place. On long pulls I hear more exhaust noise than engine noise. When I first bought it my foot would get hot on long hills. I have an old 454 eng that makes max torque at 1800 rpms. I don't know how a higher revving V-10 responds to extra insulation but I would imagine it would help greatly also.