73 charger,, change to a ralley gauge dash

[texas charger 73]

 my 73 charger has the sweeping speedometer and I want to convert to the ralley dash...what parts would I need to complete this and how hard of a job is it?

[Nacho-RT74]

Ok here I go.

Swap is pretty much straight up with all the CORRECT parts involved.

My suggestion is get a full Underdash harness from any 72/73 B body. 71 and 74 Underdash harnesses are quite different beasts.

72 could get some minor differences but way easier to match if some. For example, they are ready to hideaways setup provisions where 72 don't ( so they got quite more accesories feeds around and hideaways trigger ). Maybe will requiere to check the bulkhead terminals positions with your existant Standard cluster setup to match perfectly with ebay harnesses. I can't recall if some really changes but if so, could be just couple of wires turned around. Accesories harnesses also changes a little bit ( like AC if equipped ) but you can switch your existant to the new one without problems

They use to be cheap on ebay. No need for new harness

Why 71s doesn't really work on a plug and play job ? 71s got unexistant fasten seatbelt wiring, diff driver side door jam switch, diff wiper switch plug, and some more wires turned around. Not hard to do anyway, just talking if you want to match your car wiring and devices easier.

74 underdash harnes is NOT definitelly an option unless you have the skills to work patienlly on wiring. They got really bigger differences on wiring.

Can you convert your existant standard harness to rallye ? once again, yes if you have the skills for it. Wires arrive individually to all the cluster around, where standard gets a multipin plug to feed a printed circuit board.

About cluster itself...

nothing major to make mantion, but just depending on what do you want.

3 Rallye clusters available... basic, with clock, and with tach, where the clock and tach clusters are the same but just the gauge changes. basic is a diff beast with diff gauges non interchangeable with the others, but speedo.

then allong the years some other minor differences

from 71 up to probably earliers 73 ( or maybe those with manual tranny ) got 150 miles speedos with red high beam vertical notch indicator, where rest of 73s and all 74s got 120 miles speedos with blue high beams horizontal notch indicator

74s got an extra icon lettering on bezel at sides of light and wiper switch.

take in mind the wiper switch. Is diff from standard cluster and as mentioned on harness deal, 71s are diff from the rest. Will need to match your speeds motor too of course

Knobs are diff too ( both, light and wiper ). My advice? get the most complete Cluster you can find and will save headaches.

[NHCharger]

I believe there are a couple of threads relating to this.
I swapped the granny gauges for a ralley dash on my 72. As Nacho mentioned there is a difference in the years on the third gens. I used a 73 cluster for the 72.
I did not swap out the entire under dash harness. The granny gauges have a circuit board with a (I believe) 18 pin connector that the under dash harness plugs into. I simply removed the cluster, cut the pin connector off the dash harness, and then spent the rest of the day tracing wires. A FSM really helps at this point. this is also a good time to check the rest of the wiring while the cluster is out. There is a product called liquid tape that you can buy at Home Depot. It's just a liquid rubber you can use to cover any bare spots you may find on the wires.

You will also need to replace the oil sending unit since it won't be compatible with new gauges.

[Nacho-RT74]

yes! forgot about the oil sender!

[NHCharger]

yes! forgot about the oil sender!