I plan to replace all of the firewall and fender rubber grommets in the engine bay. Some are just missing and others are dried up, crusty, or falling apart. The first step was to inventory all of the holes in the engine bay that need grommets to get a sense for what size I need to order and the quantities of each. I used my calipers to measure the diameter of each hole in the engine bay so I can get the right sized replacements.
This post serves as a photo record of the engine bay grommets, starting in the front driver’s side corner, working my way back around the firewall toward the passenger side and back down the inner fender on that side. The area with torn metal that is bare in spots I believe is where the fuel filter bracket originally hung.
The first was down on the lower inner driver’s side fender. The diameter of this hole was 3/4″
Moving back in the direction of the firewall, another grommet in the fuel line hole just over the wheel well. This hole was 1 1/4″ in diameter. Also shown in this photo, further back on the same fender from the fuel line grommet (near the steering column linkage) was another grommet in a hole in the fender with a 1 1/8″ diameter.
In the upper firewall above the shelf and next to the hood hinge, there was another grommet, this one in 1 1/8″ diameter hole. Shown also in this picture is another hole, located to the right of the first one in the upper fender (without a grommet). That hole was 7/8″ in diameter.
Then, pictured just to the right of the master cylinders, two small holes for the hood release (1/2″ diameter) and choke cable (3/4″).
And another small one on the other side of the steering column, 5/8″ in diameter.
Two grommets for the heater core inlet and outlet, each 1 1/8″ in size.
There were two more large holes in the firewall to the left of the heater core. I later determined that these were not original, had been drilled by a previous owner, and plan to weld them up.
On the passenger side of the engine bay, also up high above the fuse box near the hood hinge, was a larger hole with grommet for the engine bay wiring harness. That one was 1 1/8″.
Another hole was located in the lower fender with grommet for the brake line. That hole was 1 1/8″ in diameter.
And closer to the front of the engine bay in the upper fender over above the battery shelf, was a small 5/8″ diameter hole and grommet. Not shown, there was another hole identical in size to this one on the opposite fender.
Below is a diagram I created of all of the engine bay holes that require grommets in my 1964 L320. The letters represent the different grommet sizes. This should be reasonably consistent with 320s from other years.