Topic: 65 GT vs 66 gauges

[Madisoneyes]

What's the difference between 65 GT and 66 gauges? I have a 65 but am finding more 66 OEM gauge clusters on eBay.

[midlife]

The only difference in the gauges themselves is the ammeter.  The 65 is induction-based; the 66 has two input posts on the back.  The rest of the gauges are interchangeable.  There is a difference in the dash cluster bezel between the two years, however.  One year is a complete surround; the other is only the top and half-way down each side.

[sgl66]

There is a difference in the dash cluster bezel between the two years, however.  One year is a complete surround; the other is only the top and half-way down each side.

I think you may be referring to what is described in here under Bezel and Dash?

http://www.mustangdreams.com/verify-1965-1966-mustang-gt.htm

My 66 has #3 dash and #6 glove box

Note that the author has updated the section to reference style 3 & 6 on non-pony cars

[Madisoneyes]

So what sort of problems will I have adapting a falcon style rectangular speedometer in my 65 to the 65 GT gauges? (I know the wiring harness is different)

[NEFaurora]

You'll have to change the oil sender and its end terminal....as the oil sender for the falcon style cluster for the idiot lights is a completely different design...  The oil sender for the five dial cluster is different and has a different end terminal...

)

Tony K.

[67gtasanjose]

So what sort of problems will I have adapting a falcon style rectangular speedometer in my 65 to the 65 GT gauges? (I know the wiring harness is different)

Pretty much everything wire related is different from the under dash wiring on out to the battery, the dash board steel itself is actually different too!
This is another common assumption that "the only thing different is just the cluster and a couple of other "easy fixes". Not true on this idea and as mentioned earlier, 65 is different than 66 so mixing parts will get you potentially "all fired up" and who wants to suggest any idea that could end up causing an electrical fire...Not ME!

Regardless, you will likely NOT get a lot of clues from here mostly because your request is outside the boundaries of this forum's primary objective, that of offering and finding information on CONCOURS resoration and repairs. IMHO, the round gages sure look nicer than the Falcon style but butchering your car's wiring to make it happen, might be a huge mistake.

Hope I didn't ruffle any feathers...but I've been known to be brutally honest at times.

Richard

[NEFaurora]

The ideal thing here "if you're really willing" to convert your 1965 dash to a five-dial cluster.., is to buy a complete 1966 underdash harness for around $500.00  Many people have done this before and it is quite successful. Of course getting a nice harness from a 1966 junker is ideal as it will save you the bucks.  In 1966, The same underdash harness was used in ALL model mustangs regardless of engine size.  Of course in reality, only 1965 GT V8 cars got the five-dial cluster.

)

Tony K.

[jwc66k]

The ideal thing here "if you're really willing" to convert your 1965 dash to a five-dial cluster.., is to buy a complete 1966 underdash harness for around $500.00  Many people have done this before and it is quite successful. Of course getting a nice harness from a 1966 junker is ideal as it will save you the bucks.  In 1966, The same underdash harness was used in ALL model mustangs regardless of engine size.  Of course in reality, only 1965 GT V8 cars got the five-dial cluster.

You will also need the under hood harnesses, alternator harness, and maybe the tail light harness as well.
Jim

[Richard P.]

Are you restoring your car for concourse judging? If so the 1966 wiring harness in a 1965 wouldn't be correct. You can also get a wiring harness from any 1965 (6 cylinder or 8 cylinder Mustang) that came with deluxe interior/ pony interior and it will work with the 1965 5 dial instrument cluster.

[midlife]

The ideal thing here "if you're really willing" to convert your 1965 dash to a five-dial cluster.., is to buy a complete 1966 underdash harness for around $500.00  Many people have done this before and it is quite successful. Of course getting a nice harness from a 1966 junker is ideal as it will save you the bucks.  In 1966, The same underdash harness was used in ALL model mustangs regardless of engine size.  Of course in reality, only 1965 GT V8 cars got the five-dial cluster.

  )

Tony K.

There's another complication in converting 65's to 66's.  In 65, there was an early 2 speed heater and a later 3 speed heater.  It is much more difficult (I recommend the customer replace the heater!) to convert the two speed system to the later (and 1966) three speed wiring system.  The later 65 3 speed heater is directly compatible with the 66 wiring; the early 65 is not.