I completed the Rocketman Ammeter to Voltage gauge conversion.  I also installed quick disconnectors for the dash wiring to make removing the dash panel in the future less frustrating ... which I'm not planning to do!

As TKO indicated, people around here have said to avoid Craigslist and eBay.  Seems Facebook Marketplace gets a lot of positive reviews.
To get an idea of pricing, check out these two sites.
https://bringatrailer.com/
https://www.classicautomall.com/

Rudi - subtle "enhancements" (without going overboard) give these cars a nice personal touch.  The few that recognize these details usually appreciate the effort.  

I also have  a Spectra 22-gal tank that I installed last year when changing to an EFI system.  I also purchased via RockAuto. 
I purchased the modified filler neck from CJ Pony and found the 'indexing' for my 1965 gas filler cap was off by about 3/8" when tightened.  This cap is a repro unit that I purchased over 20 years ago and is fit the 16-gallon tank's OEM filler neck w/o issues. 
When tightened the cap it was at about the 5 o'clock portion to vertical.  I couldn't tighten the cap any more to make it fit properly.  CJ Pony did replace the filler neck, but this replacement was the same as the first (not a surprise).  I ended up grinding (with a die grinder) the tang on the filler neck until the cap fit correctly.  

TKOPerformance wrote:

And this is why we need to make stuff in America again.  I ran into this last week with a machine screw (or so it seemed) for a ceiling fan I was installing.  Seemed like a 10-32, but wasn't.  Wasn't a 10-24 either.  I also tried an M5x0.70 I believe.  Nope.  Some baystard Chinese thread, probably some metric size not commonly found like an M5x0.50 or something.  If it was made in the USA it would have been a 10-32, 10-24, or 1/4-20 and my problem resolved in a 5 minute trip to the hardware store.  No, instead it ended with a tap and die set and a lot of 4 letter words and disparaging comments about various administrations and the PRC. 

I've run into similar issues with "small hardware" that I couldn't find either standard or metric taps or dies that fit.  I did the same thing, tapped it to a tread I had screws that fit.  
 

Jim Bowie wrote:

I was told that the Pertronix kit will not work in aftermarket distributors

Seems strange, did they say why it wouldn't work?
 

I believe another difference is the stock 65 dash has a single light for both left and right turn signals.  I believe the GT dash has separate lights for these (like the 66 dash), so a wiring change would be necessary. 

John Ha wrote:

Cab4word67 wrote:

OK quick queston on the gas gauge. I have a 65 coupe an switched over from the stock dash to the GT dash from a 65. Will the gauge read the same. I used to go into the E line and still have 2 gallons left. Just wondering if this will be somewhat the same. I am getting very close to the line and will carry 2 gallons of gas just so I dont run out but I want to know where really low is and hope its close to the same place.  

Electrically, yes.  The gauges operate the same.  The new gauge may be adjusted slightly differently though (there are mechanical adjustments on them).  If possible, check the "new" gauge against the old gauge by making sure the new gauge reads the same as the old gauge with given levels of fuel in the tank.

Another issue that would impact the reading is the CVU.  These units regulate the voltage to about 5v, but there can be minor variations that could affect the gauge reading.  
 

MS wrote:

I squeezed out about 1/4” drop of paint on a piece of cardboard and had plenty to do two sets of gauges, so there should be enough paint left in the bottle to do another 200 sets or so. Help me think of another use for it so it doesn’t go to waste.

LOL
 

BobE wrote:

TKOPerformance wrote:

It clears.  I have a factory AC compressor on my car.

Ron, some people may just be luckier than others on the bracket.  Mine failed.  There are a bunch of posts about failures on various forums.  Having messed with accessory drives on various makes and models over the years I can tell you no factory mounting system is anywhere near the way Borgesson mounts that pump, basically relying on bolts and spacers, which can flex with no triangulation.  Overall they build a great system, but the pump bracket and lower column bearing leave a lot to be desired. 
 

Like Ron, I’ve had my Borgeson pump installed since 2011 and haven’t had any issues.  I do understand the two-point vs. three-point mounting arrangement discussion and agree a three-point system would be ‘better’.  I’m going to pay closer attention to my setup in the future.   

 

As I installed a Vintage A/C system a few years ago, the mounting for the PS pump was changed, and is now a three-point support, very solid.  
 

TKOPerformance wrote:

It clears.  I have a factory AC compressor on my car.

Ron, some people may just be luckier than others on the bracket.  Mine failed.  There are a bunch of posts about failures on various forums.  Having messed with accessory drives on various makes and models over the years I can tell you no factory mounting system is anywhere near the way Borgesson mounts that pump, basically relying on bolts and spacers, which can flex with no triangulation.  Overall they build a great system, but the pump bracket and lower column bearing leave a lot to be desired. 
 

Like Ron, I’ve had my Borgeson pump installed since 2011 and haven’t had any issues.  I do understand the two-point vs. three-point mounting arrangement discussion and agree a three-point system would be ‘better’.  I’m going to pay closer attention to my setup in the future.   

 

Sorry, I can't offer a guess.  It may help to ID what year Mustang this is.