Firewall hole location for Tach wire

[westie47]

I'm adding the in-dash factory tach in my Coronet and am wondering where the tach wire passes through the firewall. Any pics with location/hole diameter would be appreciated. My search on here didn't turn up anything.

 

[moes]

right side of the black mark nexted to the bulkhead, there is a dimple

 

[Nacho-RT74]

I guess the same than Chargers with Rallye cluster ( 68/70 )

 

[1 Wild R/T]

This is my 68 Coronet R/T factory rally dash with Tic Tic Tach... The same as a Charger...

 

[65-440]

Why not just use an empty bulkhead connector spot?

 

[Nacho-RT74]

Maybe he wants to be on the correctness side of the build

 

[westie47]

Yes, I am wanting everything to look correct, plus the tach wiring harness already has the grommet on it.

 

[westie47]

This is my 68 Coronet R/T factory rally dash with Tic Tic Tach... The same as a Charger...

View attachment 1215908

Do you know what size the hole is?

 

[NoCar2023]

What size is the grommet? Measure the OD but inside of the lips.

 

[1 Wild R/T]

Do you know what size the hole is?

I'll try to remember to measure it today

 

[1 Wild R/T]

Well... I'm gonna call it 7/8" 7/8" = .875 the hole actually measures .886, so .011 oversize...

 

[69hemibeep]

I used a step bit just yesterday and stopped at 13/16 and the grommet fit