Anybody 'DD' an old slant-six?

I've been noticing a lot of old Chrysler Valiants for cheap lately, (relatively cheap, anyway).

This '69 Safari Wagon has my attention at the moment. Manual trans (3 on the tree?), and my favourite body style. Although probably just a phase that'll pass with the next car to take my fancy, I am curious...

What sort of mileage does one get? And, can they handle and go faster without spending a lot of money?

I do sometimes. My mpg sucks though, maybe around 14. I have a few vacuum leaks to chase down. I have a '75 Duster with a '71 Slant-6 in it. First thing to do is swap to a GM HEI setup, best thing ever on that car and super easy. You can then run a wider plug gap. The power isn't mind blowing, but smooth and torquy with the slant. I am running a '78 Volare 2-bbl setup on mine which I have been told is a great improvement over the 1-bbl power wise, but will suck down gas unless properly tuned. I was just thinking this morning that I needed to drive the Duster today.

As for handling, there is stuff out there. If it doesn't have a front sway bar you will need a special setup that most sway bar companies have, not too expensive either.

If you are looking for power though, get a V8 car. The slant is a cool motor, but getting big power from it is tough to do without spending cubic dollars.

I DD'd a 1980 Aspen for roughly 6 months until the auto trans blew up. I had a short commute and never took it on a trip longer than 60 miles or so.

It had a 1 barrel carb on it. Got about 20mpg in town. It was slow but fun. Never let me down until the trans went.

In reply to Luke:

That car is begging for a 340 / 360 swap. However, you can get decent power (200 - 250 HP) out of a Slant Six with cam, intake, carb and headwork while keeping it streeatble. Offenhauser still makes a four-barrel manifold for the 6.

Handling is easy. There are sway bar kits, huge road race torsion bars are available and heavy duty rear springs are a phone call to Summit away. Koni used to make shocks, but there are other options available (QA1, etc.)

What do you consider alot?

The freight bill from Summit to Western Australia might make it a little less appealing though.

Thanks for the input.

Would a wagon have the same rear suspension as the sedan? (I'd really want a wagon).

As for 'a lot', I dunno, say, a couple of grand? I wouldn't spend much more than that modifying any car at this stage of my life.

I am watching this thread with interest because a Dart wagon with slant six is on my bucket list.

I dd'd a 81 dodge d150 with a 225 and a 3spd o/d for about three years. Mileage sucked, I swapped a diplomat motor in and got better mileage. Back then it didn't much matter at .99 a gallon but now I wouldn't leave it slant six unless there was a value to originality.

I did an '84 D-150 for a while, four speed. I don't remember the MPG, but I couldn't kill it. 2WD.

My Dart ended up getting transfered from DD duty a while ago once I tried turboing it. But I can answer some of your questions.

I'd say 20 mpg is about reasonable.

Sway bars and good shocks make a huge difference in handling. You can also upgrade the torsion bars and leaf springs as they're a bit soft by modern standards, but I would definitely put sway bars on it first. I'd go front and rear - some people seem to prefer front only; it depends on what you're doing for rear springs.

1962-1976 US market and 1962-1970 Australian A-body suspension is like Legos, pretty easy to swap from different models. Wagons have the same basic rear suspension design, although I suspect many of them would have had stiffer rear springs. Pretty sure the stiffer rear springs were optional on the other body styles though.

I drove, DD, a '77 Dodge Aspen station wagon that my Dad gave me, mighty slant six and all. I would load it up and pull a 4,000 lb boat to the lake (I added aftermarket rear springs). Not much on looks, but that engine and drivetrain were great. Loved that car much more than I thought I would.....

The Aussie market had hi-po Slant 6 options available. You might want to sniff around.

I drove my '64 Valiant almost daily until I got a company car, and still use it as a frequent cruiser. 225 with a pushbutton 904 and 2.94 gears, upgraded brakes and suspension. Stock manual steering is slow, but there are options to improve that.

It has seen a best of 26 MPG on the highway, usually low 20's highway, high teens around town. Acceleration? Haven't done much on that front yet.

FYI, early A's are generally lighter and have a little less cross section for better aerodynamics.

The best source I know of for Slant Six specific info is the Slant Six Forum.

my parents DD a super6 aspen sedan (76ish?) when i was a kid. my only memories of that car are cutting my fingers repeatedly (i guess i wasnt the brightest child) on the chipped chrome door locks, the fog that would roll in through the vents when the AC was on max, and that it could chirp the tires from a standstill, sometimes.

and my friend got a free super6 aspen wagon a good couple years back, and it ran like a top but eventually collapsed on its leaf springs due to rust.

sorta related - i DD my 230 I6 camaro for about 5 years before stripping her down

Low 20's highway, high teens around town in the '66 I drove for a while. If it's got the manual trans already, you can swap in the OD trans and play with rear axle ratios to dial in for your driving.

I believe you need to google "Clifford performance"

Holley made a 1-bbl Pro-jection TBI specifically for straight-6 engines. I bought the whole set up new in box for my Dad's dart for $300.

there's one like this ( 'cept not is as good a shape ) running around my hometown ... in the mid-70's I had one

In reply to oldopelguy:

Did you ever install the TBI? Port FI seems like a great improvement to these cars...

Good info, thanks y'all.

I think, mainly, I like the legendary reliability/indestructibility of the slant6 engine.

turboing a slant six is pretty easy and generally has good results as long as your expectations are based more on drivability than dyno plots.

I recieved this 71 Valiant with a 225 slant 6 from a relative and then repainted it with lacquer in the original color back in the 90's. Daily drove it for years and traveled most of the Eastern US with it racing BMX nationals. The 1 barrel needed rebuilding about every 10-15 thousand miles (less than an hour to remove rebuild and reinstall). I experienced valve recession from not using leaded gas on long high speed trips and had to use an additive after adjusting the valves. It was very reliable right up to the point the friend I sold it to rolled it into a ditch. Miss that car.

Ok, the wagon is cool and then some. Some sort of EFI retrofit and and a 5 speed should be a good improvement. A 4 speed may help with it's better gear spread despite the lack of O/D.

You know you guys are killing me right now. Nooooo you don't want that wagon! Horrible gas mileage, handles like a barge. WHERE IS IT!?!?

Gearheadotaku wrote: Ok, the wagon is cool and then some. Some sort of EFI retrofit and and a 5 speed should be a good improvement. A 4 speed may help with it's better gear spread despite the lack of O/D.

In the US, there was a 4 speed O/D (basically a 3-speed with an overdrive 4th) manual that was fairly common behind the /6. I don't think there are any factory five speed options out there, although I'm sure the Kiesler folks would be happy to make you a custom bellhousing for their tremec if you shoved enough dollars in their faces.

Then again, things may be different in OZ.

psteav wrote: In the US, there was a 4 speed O/D (basically a 3-speed with an overdrive 4th) manual that was fairly common behind the /6. I don't think there are any factory five speed options out there, although I'm sure the Kiesler folks would be happy to make you a custom bellhousing for their tremec if you shoved enough dollars in their faces. Then again, things may be different in OZ.

I've also seen a couple slant six to Chevy transmission adapters floating around that could potentially be used to put a Camaro 5 speed behind one. Some guys have managed to stick an Aisin trans out of a Supra behind a slant six with some fabrication, as well.

psteav wrote:

Gearheadotaku wrote: Ok, the wagon is cool and then some. Some sort of EFI retrofit and and a 5 speed should be a good improvement. A 4 speed may help with it's better gear spread despite the lack of O/D.

In the US, there was a 4 speed O/D (basically a 3-speed with an overdrive 4th) manual that was fairly common behind the /6. I don't think there are any factory five speed options out there, although I'm sure the Kiesler folks would be happy to make you a custom bellhousing for their tremec if you shoved enough dollars in their faces. Then again, things may be different in OZ.

They sold those same transmissions to GM for their 6.2s. I have one behind the 350 in my truck - love it. Seriously. I wouldn't swap it for anything unless I was racing. The spread is wider than a 5 speed, but at the end of the day, so what? Nothing's cooler than the 1-2-3-OD knob, too.