I have two large holes in the firewall on my 67 SS originally equiped with a 4 speed muncie and non AC if that matters as far as these holes go. One is on the pass. side and just to the side of the trans tunnel, about where the firewall meets the floor. It is about 1" in diameter. It now has a rubber grommet in it, that sort of looks like a cowl induction wiring harness grommet. I am not sure what this hole was for originally, and if this grommet is what orginally was there. The other hole is about 1.5" in diameter and is below the steering column. It has no grommet in it and I believe originally had the speedo cable passing through it. What are each of these holes for?

Any photos? 66/67 firewalls had a lot of potential hole locations due to many options possible. Passenger side hole sounds like the speedo cable since a 4-speed cable exited the trans on the passenger side in 67.

I posted in the performance section and think I got it. Smaller hole on pass. side is for pre 67 body with a muncie with pass. side speedo hookup. Larger hole under sterring column is for 67 and on with driver side mucie speedo hookup.

I posted in the performance section and think I got it. Smaller hole on pass. side is for pre 67 body with a muncie with pass. side speedo hookup. Larger hole under sterring column is for 67 and on with driver side mucie speedo hookup.

The drivers side is for the HD 3 speed Warner ...which had the speedo hook up on that side of tranny.And the 4 spd Muncie on pass side ,but either way thats what those holes are for.

So with a 4 speed equipped car. Was there a grommet installed in the hole on the drivers side for a 3 speed or automatic equipped car. Anyone know where to get one?

It appears Year One has the one for the driver's side hole. Don't know about a grommet for the pass. side hole.

Is this a grommet without a hole for the speedo or a solid one without a hole? Thanks.

The catalog shows it as a grommet with a hole. It also states that it is a reproduction and does not have the metal insert.

Hi,

I am plugging the same holes in my '67.

Ground Up Restorations http://www.ss396.com/chevelle_64-72.htm have the 1" plug....Page 34 in their catalogue ( OEM Nuts and Bolts).

I just picked up a plug from work today and will try tomorrow for the 1 1/2 inch hole. If it works I will let you know where you can pick one up. They are pricey but if the diameter is correct it should fill the hole and look good cosmetically.

Hey Charlie
I have been looking for a 11/2" plug for my 67 S.S any luck?

Ed

I found one last week. It is the largest floor pan plug they sell for a Ford Mustang:o :D . I was looking for another plug/grommet and looked up the number on the plug. Turns out that one was for a Ford one as well. My father worked at a Ford dealer for years. In the 60's/70's he said new cars would have their floor boards littered with body plugs, grommets, bolts etc. so he acquired quite a collection. So a lot of the plugs and grommets used on our cars were ford pieces from his collection. At any rate we have a local Mustang restoration supply store right down the road so I went down there and found the plug I was looking for. While there I asked about a 1.5" for the larger speedo hole and it was the largest plug he had out of a plug kit for the Mustangs. That speedo hole is more like 1 9/16 but that may be due to the irregular shap of where it is at. At any rate the plug I bought snaps into the hole fairly well. It is a touch on the loose side but I used a hammer and punch to slightly knock some of the dimpled out areas in and a tad of silicone in a couple spots will hold it securely. It was only a $1. The local Ford dealer could still get the smaller one I was looking for, but they had to order them, and I never asked them about the larger. They actually pulled it up with the number off the plug. I will get the number off the 1.5" plug tonight and post back with it. Call your local Ford Dealer and give them that number and hope for the best. Or, call TJ's Mustang in Salem, VA with the number. I will post back with their number as well.

Sorry for not posting back yesterday, but my day got real hectic. The number on that large plug is 377901-S. It is listed as a seat access hole plug for a 64-70 Mustang. The number for TJ's Mustang Supply & Body Shop here in Salem, VA is 540-387-3863. Good Luck.