I recently replaced my firewall pad and as Mike B stated, you have to remove most of what passes thru. My main harness passes thru the pad in the upper left side, about two inches from the side. I slit the pad so I did not have to cut and splice the harness. You can’t see that area without crawling under the dash, so it didn’t matter to me. I also replaced the floor mat and added a pad to that too. It helps with the noise and helps insulate the floor from engine heat. I removed the clutch, brake, parking brake and gas pedal so I didn’t have to slit the mat.

Since most of what passes thru the firewall is removed, it’s a good time to replace all the grommets to help seal up the holes in the firewall.

Here is the post on installing the firewall pad. https://www.stovebolt.com/ubbthread...irewall-pad-for-52-3100.html#Post1416053

Here is the post on installing the floor mat. https://www.stovebolt.com/ubbthread...-chevrolet-3100-project.html#Post1414613

Last edited by Phak1; 09/28/2021 1:00 PM.
Phil
Moderator, The Engine Shop, Interiors and Project Journals

1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube
Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes
Project Journals
Stovebolt Gallery Forum