The Super Six

Back in the 70's, emissions laws had killed off many of the hottest motors out there. The 340, Hemi, and 440 Six Pack were gone, with the remaining big blocks soon to follow. Chrysler's engineering staff resorted to trying to find ways to wring more power out of their less glamorous remaining power plants: the 225, 318, and 360. Many ideas for the slant six were considered, but unfortunately the turbocharged and injected versions never made it into production. What did, however, was a small power boost in the form of a Carter BBD carburetor and a larger exhaust. This package was known as the Super Six, and it's one of the more affordable performance enhancers out there for the Leaning Tower of Power. My setup cost me approximately $200, and that included a Lokar cable kickdown linkage that in retrospect may have been a bad idea.

Super Sixes are relatively common in junkyards that keep late 70's Mopars around. The cars which seem to have them most often are Aspens and Volares, although they may also turn up in trucks or full-sized cars. Station wagons in particular are likely to have Super Sixes, as this power pack was standard equipment on six cylinder wagons. Spotting a Super Six manifold without the corresponding carburetor is easy: It has four carburetor studs and two holes, while a conventional manifold has two studs and one hole. I've heard that there were some aluminum manifold versions of the Super Six, and that these manifolds are so porous as to be best avoided.

What you need to get is pretty simple. You'll need the manifolds (actually, the exhaust manifold isn't any different from other ones, but it's usually a real pain to remove), carburetor, choke, and air cleaner. If you don't already have a cable type throttle linkage, you'll want to grab that too. Automatic transmission users will want to get the kickdown linkage, as well. Remember that there's a manifold nut located in an extremely inconvenient location under the choke heat stove. Without getting that one off, you can bang on the manifold all you want with a pry bar or an axle half-shaft, and it'll stay stuck on tight.

Putting the manifold on will be pretty straightforward. It'll install exactly like the stock one-barrel manifold. Don't forget to replace the gasket that separates the manifolds, or you will have a very bad exhaust leak. The only problem you're likely to encounter here, besides stuck bolts holding the manifolds together and the lack of replacement off-the-shelf bolts like the ones that hold manifolds together, is again the annoying washer and nut under the choke heat stove. I got the washer on by fitting it over a piece of rolled up paper, sliding the paper roll over the stud, and letting the washer fall off onto the stud.

If you're using the carb from the junkyard, you'll almost certainly want it rebuilt. Carbs can accumulate a lot of gunk in them while sitting in a junkyard. I've heard there is a problem with worn throttle shafts, so you'll want to watch out for that.

The throttle linkage requires some creativity if you don't already have a suitable cable linkage. What I did was take the pedal out of the Aspen, find a suitable place for it on the floor, and mounted it with the aid of a simple bracket I made from a piece of sheet metal. Then I drilled a hole through the firewall and put a new throttle cable through it, where it hooked up to the bracket on the manifold. The result looks almost, but not quite, like it was a stock setup.

Now, if you've got an automatic transmission, comes the part you'll really need a good supply of obscenities and curses for. On some A-bodies, and certainly F-bodies, the kickdown rod will just bolt up like it did on the Aspen. On other models, like my '66 Dart, the kickdown rod won't work without considerable bending. While I don't have any plans for just how this is to be bent, it is the way I would recommend making the kickdown work.

It is not what I did for a kickdown, however. I ordered a Lokar Hi-Tech kickdown cable kit. While it was certainly of high quality, it was next to impossible to install! It took my father and me several hours to connect to the transmission, due to how cramped the area around the kickdown lever is on A-bodies. And that was the easy part; the other end would have required a completely custom made mounting bracket to adapt to the carburetor. Lokar claimed that the linkage is "adaptable to all type manifolds", but either they had never heard of a Super Six or meant it was adaptable to my manifold in the same sense that a supercharger kit for a 5.0 Mustang is adaptable to a Slant Six - in other words, adaptable if you've got a reasolably well equipped machine shop and are good at custom fabrication.

I decided to go an easier route: adapt it to the accelerator pedal. I cut a bushing just a bit smaller than the bellcrank the accelerator pedal is attached to in half, and secured it over the bellcrank with a hose clamp. I then ran the cable through a hole in the bushing, so the kickdown cable works almost like a second throttle cable. It may not be pretty, but from all indications it works. I'd suggest trying something else, though, and leaving Lokar cables to those who prefer four-barrel Hollies.

Super Sixes come with an electronic choke pull-off assist. Either hook this up to an electronic choke assist controller, or leave it disconnected. Whatever you do, don't hook it up to a constant 12V source, or it will pull the choke off too fast and give you some serious problems driving with a cold engine!

Once I got the Super Six in tune, or some semblance of being in tune, the improvement was very noticable. My Dart is now much quicker off the line, boasts vastly improved throttle response, and seems to have more power at almost all areas of the RPM range. Plus, the vapor lock and hot starting problems I had with the Holley 1920 are a thing of the past. While I was somewhat disappointed with my first attempt at running the Dart at the dragstrip after installing the Super Six, I think this may be due to the wear the engine has accumulated in the nearly 200,000 miles it's been through.

Big Fat Legal Disclaimer: I don't guarantee spectacular results from installing a Super Six. These are junkyard parts we're talking about, after all, and they vary greatly in quality. And I have no idea how competant anyone reading this may or may not be with a wrench. As a matter of fact, I really can't put any kind of guarantee or warantee on this information at all. Hey, it's free advice, and you get what you pay for. I assume no liability for any damage, economic, physical, or emotional which may result if you follow this advice, especially if you do something stupid while installing it or driving the vehicle.

Check your state laws about emissions legality. Although you can probably get your Super Six tuned so it will pass a smog check in most states, the bureaucrats in the Peoples' Republic of California probably won't see it that way. All they are likely to care about is that it was neither a factory original part for your model year (it never was availible in California) nor a CARB approved aftermarket part. As much contempt as I have for some of the more poorly thought out pieces of emissions laws, I don't actually advocate disobeying them.