• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

GM to Mopar- I know, this might be sacrilege...

Phantom440

Well-Known Member
Local time
3:54 AM
Joined
May 7, 2010
Messages
105
Reaction score
24
Location
Maryland
Hello all;
I have a question I'm hoping won't get me too much hate. Please keep in mind this is the only non-Mopar part I'm using, and this is going into a '72 4-door, so I'm not corrupting something collectible like an R/T Charger or anything. :)
I've had this idea for years, and while I was inside the car doing the auto-to-manual pedal swap, I also took out the dashpad and the door panels to paint. While I had it all apart, I figured now was a good time to try this idea: A repro GM hood tach on my dashpad. Right now it's just kind of sitting there, not attached at all, but my question comes to the wiring. I got this tach from Parts Place, and the description says it will work with old GM points ignition, or an HEI type system. The Coronet has an orange box system. Will I need a tach adapter to use this with the orange box, or could the wiring remain the same as stock?
(I know there have been many posts here about adding a tach, and I've studied up on the diagrams attached. Since this is a GM thing, I didn't know if that info would still apply.)
Thank you in advance for any help, and hopefully not too much hate! ;)

406C4935-A9BA-49CE-A3C3-B8823AB59CDC.jpeg 98A25272-9BD6-4083-AD08-ECFAEA9DBCB7.jpeg
 
I think it will work with the orange box. Looks pretty cool to me. Some of the Pontiac's had hood mounted tachometers.
 
I've heard that's half the reason the hood tachs were so unreliable, they're mounted outside in the rain and cold, then subjected to the heat from the engine, they'd build up condensation on the electrics and on the glass, so either the electrics got fried or you couldn't see it through all the water on the inside of the glass. I figured bringing it "inside" would solve some of that. :)
 
That's a Dixco tach. They were also made for other brands of cars including Mopars.
 
I've always had a peeve about people bolting or screwing tachs to otherwise nice dash pads. Probably because it was so unusual to see 60s and 70s cars with un-cracked dash pads even in the 80s.


FYI, you can get an aftermarket tach that mounts where the factory clock is on the 71-74 non-rallye dash cluster.
 
I've always had a peeve about people bolting or screwing tachs to otherwise nice dash pads. Probably because it was so unusual to see 60s and 70s cars with un-cracked dash pads even in the 80s.
FYI, you can get an aftermarket tach that mounts where the factory clock is on the 71-74 non-rallye dash cluster.[/QUOTE]

In all sincerity, I share that pet peeve, however this dash pad is pretty crusty... luckily no big cracks (yet), but it's not nearly as nice as these pictures make it seem. I painted it the weekend before I did this, so maybe that makes it look nicer than it is. :) The only trimming/drilling I had to do was a tiny little corner where it meets the speaker grille, and I cut the speaker grille area to let the wires come through.

Regarding the tachs that fit into the clock space, I have a police-spec gauge cluster with the oil pressure gauge in that location. It's not in the pictures, I need to drop the column first to get that cluster out and swap the new one in.
 
This is actually my wallpaper on my work computer, hahaha...

Screen Shot 2018-03-09 at 3.17.07 PM.png
 
I almost did that cop oil gauge in mine, but have a rallye cluster to go in eventually.
 
Auto Transport Service
Back
Top