New the forum but not to slant 6's. I had a mint 73 dart swinger with 48,000 miles from 92-99. It was garaged its entire life until my grandfather (the original owner) moved in with us (1992). It was just too nice to be sitting outside so I sold it to a gentleman who keeps it garaged and drives it on weekends.

Anyway, one of my grandfather friends (my mom’s side of the family) has a 73 dodge D100 with 73,200 original miles that he thought about selling. After I showed interest in it, he decided to give it to me when he passes (he's 86 and shouldn't be driving, but that's another story). Anyway it hasn't had a tune up in god knows how many decades. You know how old people are; they don't fix anything until it completely breaks.

Here's what I'm thinking.

1) Valve adjustment (never been done and noisy). Which valve cover gasket should I get? I remember having better luck with the rubber ones on the dart.

2) Plugs. What is recommended? I've read something about NGK's.

3) Distributor cap and rotor. What brand(s) are recommended? I have a set of original mopar wires for it. Those should be fine I assume.

4) Charcoal canister filter. I bet it has never been changed.......if it's still there at all.

5) Clean and re-oil the breather element.

6) New PCV valve. What brand?

7) New thermostat and coolant change. What temp thermostat is recommended? I remember using a 195F in the dart and it was too hot for the summer months. The 180F seems to work best all around. Any brand better than the other? Probably should change ALL coolant hoses, they look original.

Fuel filter and rubber lines (since they're currently leaking). I read somewhere about staying away from the glass style fuel filters. Any info?

9) New vacuum hoses

10) Eventually rebuild the carb. It has the 1920 Holley on it, fond memories of rebuilding that thing on the dart. What brand rebuild kit is recommended?

Anything else?

The D100 is a three speed column shift manual trans. First and second gears sound like they're about to explode. Those 73,000 miles are mostly 1st and 2nd gear driving since it was town driven 99% of the time in Reno NV. Anybody know about how much $$$ it would cost to rebuild it? The clutch is original and the pressure plate is getting weak so it's new clutch time anyway. What brand clutch is recommended? Thanks in advance.


Dan

For sure. The valve adjustment procedure is here. Truck specs were 0.012" intake and 0.024" exhaust, which is a little looser than the car specs of 0.010" and 0.020". Same engine, same cam, so your call. And yep, you'd probably have better success with a rubber gasket, but those were discontinued long ago. There's a company selling silicone rubber ones. Don't be fooled; their heart is in the right place, but that's not the right material for the job. You will probably wind up using a composite cork+rubber gasket. They work fine if your valve cover isn't bent up at its sealing rail. That's this one. Don't be tempted to apply any kind of cement, sticky stuff, or 'sealer' to this gasket or you will hate yourself at the next valve adjustment!
The old standby brands (Champion and Autolite) can't be recommended any more; quality has just plummeted. For the '60-'74 cylinder head, use NGK № ZFR5N (single plug, or money-saving 4-pack). Remove the metal ring washer before installing each plug if you're using a '63-'74 head. If you've got a '60-'62 head, leave the metal ring washer in place. See here for details on the ring washer issue.

You'll want new spark plug tube seals, too. Plug tube seals cook to death in their hot, oily location, and they have been getting less available as replacement parts at parts stores and websites, which has led some people to try substituting round plumbing-type O-rings (or worse).

If your plug tube seals are hard and crunchy instead of soft and chewy, permanently deformed into a triangular cross section, replace 'em. They start out as a square-cross-section O-ring, size № 218, so the actual-real OE-duplicate item is this in Buna-N rubber (good in most oils, good to 212 °F), or this in Viton rubber (good in a wide variety of oils and chemicals, up to 400 °F). Or if for some reason you wanna get extra super de luxe about it, there's this Viton X-section ring.

For '75-up cylinder heads that use the smaller 'peanut' taper-seat spark plugs without plug tubes, use NGK UR5 (linked plug is correct, pic is generic, though, so don't panic).
In the past, the advice was a Standard-Bluestreak CH-410X cap and a NAPA Echlin long-tip rotor № MO-3000 are the top picks. Don't use an Echlin cap; they're usually ground off-centre and the rotor can hang and lock up the distributor. The MO-3000 rotor has a contact end that's longer by 0.060", which lets you open up the spark plug gaps a little (try 0.040" rather than spec 0.035"). That information is out of date. Some of it is still factually correct, but see this thread for the problems and solutions with the caps and rotors available today. It's a long thread, but worth reading the whole thing. If you can't be bothered doing the work described in that thread to finish up the work that should've been done in the distributor cap factory (and I wouldn't necessarily blame you), your best bet for a well-made off-the-shelf cap (as of early 2025) is a United Motor Products № CC-611X cap and WVE 4R1021A rotor.

Spark plug wires: sooner or later you'll want to replace them with premium ones from Magnecor, especially if you do the HEI upgrade.

The filter on the charcoal canister is probably (over)due for replacement, and the crankcase breather and its gasket probably want replacement (you might get away with cleaning the original breather).

PCV valve: see here.
180° to 195°, depending on what year the car is and where you're driving it, under what conditions—read this to understand why this is the basic recommendation and understand what goes into deciding whether to pick something different. As with just about every other kind of part for old cars, getting a good quality thermostat is a lot harder than it used to be—mostly what's widely available is sloppily-made junk. If you're willing to dig for your supper (or thermostat), the Tridon company in Australia puts out really nice high-flow thermostats for the Slant-6 in 160°, 170°, 180°, 190°, and 192° ratings (though they're packaged with the temperature listed in Celsius). Part numbers are Tridon TT2000-160, TT2000-170, TT2000-180, TT2000-190, and TT2000-192. Mouse around on the internet and you'll find a way to buy them even if you're not in Australia.
Yeah, the idea of breakable glass (or meltable plastic, for that matter) holding gasoline in the engine bay kinda makes my beard stand on end. You get away with it unless and until you suddenly don't, and—here again—you can't trust even an old/major brand name to have used underhood-grade plastic; most likely they just slap their name on crummy dreck from the People's Republic of Box Says Top Quality. Use a metal fuel filter. You may want to do the fuel line mod. Cracked, stiffened, oil-soaked or split vacuum hoses can be replaced, but you needn't replace good ones.
Parts store rebuild kits (whether the parts store is online or in person) have deteriorated in quality, too. It's best to buy from one of the last great real carburetor people in North America; that's The Carburetor Shop ; another good source is Daytona Parts Co. Float gauges no longer come with most carb kits, see here.

Choke stuff, see here.

Throttle shaft/bushing wear and rebuild info, see here and here.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

Make sure the manifold heat control valve is working correctly, not stuck (they're often stuck). Freeing up the valve calls for a special solvent—no longer available from Mopar, but GM will sell it to you. Despite its generic-sounding name, it is not at all like any other penetrant; do not substitute.

Other stuff: as soon as you can, get the three books listed in this thread. And take a look at this post.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

On the 3 speed, going to be hard to find most of the parts since not many parts are made anymore....you may want to think about a 4 speed np435
23 spline imput shaft trans, that would be a bolt-in and cut a
hole in the floor for the shifter.....
If you want, call Dennis at http://wildcatmopars.com/
he knows more about 3 speed
manule trans than anyone I know....

_________________
http://imageevent.com/jeffc
62 D100 225 3sp lwb
64 D100 A318 727pb custom lwb
66 D100 A318 4sp lwb
68 D100 B383 727 swb
65 Belveder A318 727 4d
65 Dart GT LA273 2bbl 904
73 Scamp 225 2bbl 4spOD
Old iron or no iron

Great info, thanks fellas!! I'll be heading up to Reno on Monday to work on the D100. I pretty much remember all of the tools I need except the size of the crankshaft bolt to adjust the valves. Anyone happen to remember the size?

Interesting. So when you say bolt-in, does that mean absolutely no modifications (except the shifter hole) ie modification on the cross member, driveshaft, clutch and z-bar, bell housing and whatever else I forgot?

I was looking at some np435's on eBay and they all seem to have granny low. I was hoping to get something along the line of an 833 non-od without granny low. Is this possible? Thanks in advance, this place is great!!



Dan

The 833 4-speed with a 3.09 first gear is the lowest 1st gear ratio you will find for that transmission.
DD

Here's a thread answering the crankshaft bolt question...

http://slantsix.org/forum/viewtopic.php ... pener+bolt

Good luck with the project,
Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

Dan! whats the best type of fuel filter for my 63 dodge dart 225?!
thanks