I’ve been annoyed for some time now by the fact that the average ’60/70′s Mopar alternator stops charging when engine rpm’s drop below 650rpm orso.
Since the engine in the ’73 Dart runs on LPG, I got it idling around 500 in drive / 550rpm neutral.

During evening drives, at pretty much at every stopsign the ALT-gauge in the car pegs to almost full discharge. especially if it rains and blower-fan is on.

To solve this issue (since I don’t want to increase the idle-rpms), I wanted to try out a modern alternator and see if these things DO charge better at lower rpm’s.
So a friend got me a 90′s Ford “3G” alternator to try out. I ordered an electrical connector for it to complete it’s ‘internal’ wiring.

Another issue was the 3G-alternator uses a multigroove serpentine pulley, while my car still has v-belts. I decided to make a double row v-belt pulley on the lathe, with a slightly smaller diameter than the smallest v-belt-pulley I already had laying around.

I mounted the alternator on the engine with pretty much a simple curved strip of aluminium added to it.
I also decided to run the headlights through a relay, to keep the lightswitch from frying out and to keep from having high currents running through the bulkhead-connector at the firewall.

After everything was connected again I started up the engine and measured the voltage delivered by the alt. Even with the engine idling slowly in Drive, headlights and defrost-blower-fan on.. the alternator was still charging!

With the engine idling in Neutral the measured voltage increased to 14.4 rightaway. Perfect!

Yesterday I decided it was time for the front of the car, to meet the rear of the car, and persuade them to do the same movements together when driving.

So, I cobbled up a set of subframe connectors and welded them in place under the car.

The difference is very obvious. The car feels much more rigid and sounds more solid, and quiter aswell.
Also the front suspension is more noticable now in the car, especially the springs feel like the have just a tad more springload.

Anyway, I’m quite happy I took the step to fab up a set, for next to nothing in costs.

Lately I was finally ‘mentally’ ready to start with the transmission-swap in my ’73 Dart. I went from a 904 to an A518 transmission. The A518 is a ‘bigblock’-transmission with a smallblock bellhousing and overdrive. Later tranny’s also have a lockup-function, but mine didn’t have that. This means I can use a regular ’60s stall convertor.

Because an A518-transmission is more bulky than the 904, some considerable modifications are needed in the car like the driveshaft-tunnel and rear transmission crossmember. This is because these overdrive transmissions weren’t available on these cars and years yet.

Pic of the removed 904-transmission, which had developed some slow 2-3 shifting issues;

Pic of the 518 waiting patiently;

The top half of the transmission-crossmember had to be completely removed, otherwise the transmission couldn’t be mounted high enough in the car.
The 518-transmission also come stock with a deep oilpan, so to keep enough ground-clearance, a proper transmission height was mandatory.

To restore proper stiffness, the top of the crossmember will be welded from inside the car later on.

The bottom half of the crossmember was modified to accept a simple Chevy mount which I happen to have laying around in the garage.

After a lot of trialfittings with the transmission, it was finally time to install it properly.
It was then time to renew the coolerlines, as these transmissions have 3/8-lines, as opposed to 5/16 used by the 904.
Then it became apparent the stock speedometercable had become too short now, so a new, longer one was ordered.

With connecting the ‘kickdown’-linkage, I had to lengthen it about an inch to get the proper travel again.

Also the console-shifter linkage had some issues now.
Because of the bulky body of the transmission, the linkage could not go straightdown through the tunnel anymore. But with a slight tilt of the linkage I managed to get alongside the transmission again. Another small modification was done before I was finally able to shift through all the gearsettings again.

Finally it was time to shorten the driveshaft (again). I had shortened it before when I swapped the rearaxles.
The 518 is about 5.5″ longer then the 904. So out came the pipecutter again.
After measuring twice, I cut the driveshaft also twice )
I cleaned up the yoke on the lathe and tapped it back into in the driveshaft tube again, were, after some slight correctional taps, it was welded into place again.

All this was done a week ago.
My main concern was to get the car drivable again as soon as possible.
So I’ve only just managed to (electrically) get the overdrive unit working when I found a suitable plug.
I rigged up a simple switch on the console where I can (for the time being) control the overdrive myself.

I must say it was a pleasure feeling that overdrive-unit kick in for the first time during driving in this car. Also because I didn’t know anything about this transmission other than the PO said it should work alright.

Even with the 2.94 gearratio in the rearaxle, turning on the overdrive at cruisingspeeds above 35-45 mph makes for a nice and quiet driving car.
The motor doesn’t turn a lot of rpm’s anymore at these speeds, so getting on the throttle is not advised ofcourse.

It was a lot of work, but seeing how much it has improved the ride-quality of the car, it was well worth it.

The existing brakes on the ’73 Dart are doing their job fairly well, but the parts were getting old and worn. And when at one time I noticed a slight pull on the steeringwheel, because of a front brake caliper sticking, I decided it was time for an upgrade, since the rotors were wearing a little thin aswell.
The original disc rotors are 10.5″ orso in size, and just under an inch thick.
Since I had some fullsize Chrysler rotors at hand, I tried to see if it’s was possible to retrofit such an C-body brake system to an A-body Mopar.
After some trial mock-ups I decided it was very well possible so I went ahead with the upgrade.
The ’73 C-body rotors are a hefty 11.75″ in diameter, with an 1.25″ thickness. Plenty of heatsink-iron there.
I also used ’73 calipers, which have a larger bore than the ’73 Dart calipers. This would also rebalance the bias in the brakesystem again a bit to the frontwheels. Ever since the rearaxle-upgrade I’ve been noticing the rearbrakes wanting to lock-up fairly easy on wet roads and stiff braking.

The spindles had to be sleeved larger, so the larger C-body rotor-bearings would fit properly again.

The old master cylinder was replaced in favor of a new modern-style Mopar Performance master-cylinder with a slightly larger bore to supply the larger front calipers aswell.

All in all, this is not a real ‘upgrade’, since the entire brakesystem has become heavier than stock, but I’ve saved myself from having to buy all new parts, and just used what I already had laying around.
Added bonus is that I’m now using the exact same brake-rotor on all my discbrake converted cars!

The Dart came without a swaybar at the time I bought it, and it had a nasty tendency to suddenly oversteer while cornering. Especially on wet roads, the car would just ‘dive-in’ and the rear would break out. Better tires helped slightly with this problem, but it was obvious something had to be done about it.
After getting a used swaybar from a friend, it turned out to be one for earlier Darts. I tried modifying it for my Dodge, but decided to just get a proper made and sized swaybar instead. Looking at various swaybars, my choice fell on the Hellwig 1-1/8″ swaybar.

After mounting the bar the following testdrive showed a greatly improved ride-quality, especially when cornering. The car now pretty much went level through the corners and the nose-dive/rear-end breakout was gone.

www.hellwigproducts.com

I’ve recently started making a beefier, 8-3/4″ replacement rearaxle for my ’73 Dodge Dart.
The car’s current rearaxle is a flimsy 7-1/4″ version, with huge backlash on the gears, worn out drums AND only a 4″ wheel boltcircle. The front wheelstuds of the car already have a 4.5″ boltcircle, so this rearend is def. not worth it to spend any money on.

Since Mopar 8-3/4″ A-body rearaxles are hard to find, expensive and if found, usually also still have 4″ boltcircle wheelstuds, I decided to shorten an existing axle housing. Just for kicks!

I found 2 big 5″ rounds of aluminium and turned these into axle housing alignment spindles on my lathe. Two for the bearing-ends, and two for inside the 3rd member housing.

I pulled a larger Chrysler C-body rearaxle out of my ‘scrap pile’ and cut the bearing ends of the housing with a pipecutter. After that I also cut off the amount needed to shorten it from the housing.
In the mean time I had ordered a pair of brand new stock A-Body size axles at DoctorDiff.com

After a while I noticed something not right with the housing ends I had cut off earlier.
The rearaxle I had used was from a 1960 Chrysler, and upto 1964 these cars had a different type of axle, and I learned that day, therefore also different axlehousing ends.
So out came the pipecutter again and I pulled another rearaxle out of my partsstash… but this time I used a 1965 rear end.

Testfitting and Complete mock-up;

Now it was time the measure the angle at which the housing ends (and springperches) should end up at so everything goes well when the rear end is mounted under the car.
So out came the trusty iPhone with that nifty ‘Clinometer’ app installed!
After carefull measuring I tacked the housing ends in place and started measuring again, for good measure ya know…! After I “OK’d” my findings, I rotated the powerswitch on my welder onto setting “fullthrottle”, and I was off melting steel..!

I had never welded heavy/thick steel before but after the first inch or two I felt comfortable and welded the rest aswell, welding 1-2 inches at a time, at opposite sides.
I also mockedup some (Cherokee?) discbrakes I had laying around to see if a discbrake conversion is feesible aswell.

And there we are, one rear end, properly sized for a Mopar A-body…