Firewall Insulator Mounting Holes

[dz1087]

Getting ready to order insulation and carpet for the ol' 71. I'm planning on using the RAAM Audio Deadener and Ensolite Mat system under the carpet and along the firewall in place of the old fiber firewall insulating pad from the factory.

2 questions:

1) Is the sound deadener and Ensolite going to at least equal or exceed the heat and sound insulation that the factory placed on the firewalls in these trucks?

2) If I am not going to put stock firewall padding on there, is there any need of the holes in the firewall that were there to hold that padding on? Can I just over those holes up prior to installing the RAAM padding?