DADS50's answer that the temp capillary tube is fourth item through the 4-hole grommet in a 1950 firewall is correct. However, the FAM diagram in his link is for a 1954 firewall, which has different routing than a 1950 truck. I don't know what model year introduced the change.

The four items in a 1950 four-hole grommet are
> Oil gauge pressure pipe
> Capillary tube (temp gauge)
> Choke
> Throttle
(actually, a photo by Denny Graham of an original 1950 firewall shows the four items going through a one-hole grommet)

The speedo cable is in a single hole grommet in a 1950 firewall.

The two different firewall routings were discussed in this thread. The thread has photos of original unrestored 1950 and 1954 firewalls.
> Firewall thread

The 1954 firewall in the FAM diagram shows three items through one of the holes in the firewall of 1954 lefthand drive trucks:
> Speedometer cable
> Oil gauge pressure pipe
> Capillary tube (temp gauge)

And it shows two items through another hole in the firewall of 1954 lefthand drive trucks:
> Choke
> Throttle

- Lonnie

- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

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