A potential problem with Super Sixing my 1973 Duster.

-
T

timk225

Well-Known Member
Joined
Jun 2, 2024
Messages
82
Reaction score
45
Location
Pittsburgh
I'm planning on putting a factory Super Six setup on my 225 1 bbl 1973 Duster with AC.

I'm going to a junkyard this week to look through some F M J body cars for a Super Six setup.

I've noticed a problem that almost exists in my factory 1 bbl setup. Air cleaner to AC compressor clearance. It fits, but with less than an inch. There is no way a larger Super Six (318 size) air cleaner will fit. 1973 Dusters never had a Super Six option.

I'm thinking of the solution since Aspens and Volares (and, I think, Diplomats and LeBarons) did have the Super Six option with AC cars. I'm guessing the AC mounting brackets hold the compressor a little lower. I'll pay attention to that when I go to the junkyard on wednesday.

Anyone ever deal with this clearance issue? I didn't want to chop a section out of the air cleaner, and didn't want to use some chrome aftermarket air cleaner assembly.
 
The Super Six had its own special air cleaner clearanced for the compressor. Don't forget to look in trucks, too.
 
If you find a Super Six setup make sure to grab all the kickdown mechanism. It is peculiar to that intake and hard to find.
 
halfafish said:
If you find a Super Six setup make sure to grab all the kickdown mechanism. It is peculiar to that intake and hard to find.
Click to expand...
What he said ^^^^^ AND GET IT ALL! Everything including the kickdown lever on the transmission as it is different than the non Super Six! Good luck finding it.
 
i'll echo the above: if you find one get everything! every pin, clip, nut, bolt, bracket, whatcha macall it and whatzit that's there. ev-ree-thang.
 
Your 1bbl. air cleaner isn't going to fit the Super 6's carb anyways, so you'll need the air cleaner too- it should already be clearanced for the AC compressor. And like everybody has already said, grab ALL the throttle and kickdown linkages- and take pictures of how it is ALL mounted BEFORE you tear it off so you can see how to reinstall it all!
And make sure you take pictures and/or make notes of how all the vacuum hoses are routed and what they're connected to- you may need to grab a couple of extra fittings or gizmos that you hadn't thought about. It'll save you a return trip to the boneyard.
 
RustyRatRod said:
What he said ^^^^^ AND GET IT ALL! Everything including the kickdown lever on the transmission as it is different than the non Super Six! Good luck finding it.
Click to expand...

Yes, I will get all the parts of the kickdown linkage, throttle cable, etc. Even the exhaust manifold and its choke assembly.

But what's this about the transmission kickdown lever being different?

Longer or shorter lever? I never heard that before, although I did have a 20 year gap of no Slant 6 vehicles, 7/2004 - 7/2024. I had always set up my kickdown linkage to be pushed fully rearwards at wide open throttle. Never blew up a 904, but I did break 6 7-1/4" axles in about 11 years in various ways (wheel bearing, differential spiders, ring and pinion gear teeth, etc) with my constant hard accelerations!
 
timk225 said:
Yes, I will get all the parts of the kickdown linkage, throttle cable, etc. Even the exhaust manifold and its choke assembly.

But what's this about the transmission kickdown lever being different?

Longer or shorter lever? I never heard that before, although I did have a 20 year gap of no Slant 6 vehicles, 7/2004 - 7/2024. I had always set up my kickdown linkage to be pushed fully rearwards at wide open throttle. Never blew up a 904, but I did break 6 7-1/4" axles in about 11 years in various ways (wheel bearing, differential spiders, ring and pinion gear teeth, etc) with my constant hard accelerations!
Click to expand...
I think they are shorter, I am unsure, but they are different. If it's there, get the thing.
 
I went out to a junkyard today that I thought might have one, but they said they didn't, one of the old guys spent a half hour out in the yard looking but I wasn't allowed to go in "for insurance reasons". Yeah whatever lemme go look for myself, I know better!

Still in the market for one.

If the longer / shorter kickdown lever is an issue, maybe one reason that I never had a 904 problem (except for the time I stripped the splines out of the torque converter on a high rpm 1-2 upshift) is that I always modified my valve body according to Mopar magazines of the time, drilling a few holes a little bigger in the separator plate, and I always cranked up the line pressure adjuster screw as well.

I know of 2 other junkyards that might have a Super Six setup, but it is a slim chance at either one.
 
Last edited:
There was a write up on the /6 forum by either Greg ("slant six" is his name here) or Rick Covalt (who I think is registered here but almost never posts anything) but both "live" on the other board, where they made (fabricated) a bracket that bolted to the EGR studs and they were able to make the 1bbl factory linkage work much like it originally did with the 1 bbl...
I commented on it to "bump" it, I don't remember which forum category it was under but it wasn't very far down last I looked. It was real cool how they were able to make it work

I will have to address that soon on my super sixed truck, I liked what was done in that write up but I also have a couple of lokar cables here (3 total, I believe one "real" lokar and 2 imposter's might be the other way around) that I might try to make work. Original super 6 kickdown linkage is all but "unobtanium" even though the manifolds pop up occasionally.
 
Oldmanmopar said:
Weld the super 6 air cleaner hole into the base of your air cleaner.
Click to expand...
I have a housing from a "68-ish "Super 225" here that I'm probably going to do just this, sacrificing one of my many 318-2bbl air cleaners I have for the conversion.
 
timk225 said:
I went out to a junkyard today that I thought might have one, but they said they didn't, one of the old guys spent a half hour out in the yard looking but I wasn't allowed to go in "for insurance reasons". Yeah whatever lemme go look for myself, I know better!

Still in the market for one.

If the longer / shorter kickdown lever is an issue, maybe one reason that I never had a 904 problem (except for the time I stripped the splines out of the torque converter on a high rpm 1-2 upshift) is that I always modified my valve body accordsing to Mopar magazines of the time, drilling a few holes a little bigger in the separator plate, and I always cranked up the line pressure adjuster screw as well.

I know of 2 other junkyards that might have a Super Six setup, but it is a slim chance at either one.
Click to expand...
The transmission lever is not what I'd call "critical" but the super six lever is indeed different. It will not make the difference between burning the transmission up or not. You will still be able to get it right with the standard lever. I've done it several times. This isn't rocker science. Get as many of the parts as you can. You can use a cable setup from Bouchillon if all else fails. This ain't hard to do.
 
volaredon said:
I have a housing from a "68-ish "Super 225" here that I'm probably going to do just this, sacrificing one of my many 318-2bbl air cleaners I have for the conversion.
Click to expand...
That's not a Super Six. The Super 225 was a marketing name for the early 225 engines. They were not equipped with the 2 barrel carburetor.
 
Yup I know that. It's about 10 years before they came out with a super 6. That's why I said I'd have to cut the bottom out of a 318 air cleaner and weld it into the bottom of the "super 225" one to make it work. But I like the looks of the "super 225's" air filter housing better.... I'm also gonna have to pirate the elbow from the 318 housing for the valve cover breather....
 
Way back in 1997-2004 when I had my 1971 Plymouth Valiant all tuned up, first with a BBD and later with a Holley 450 mechanical secondary, I also had Clifford Street Rod headers on the car. My solution for the kickdown linkage was using the stock Super Six linkage and mounting brackets. After some careful measuring, since I no longer had the stock exhaust manifold on the car, I used longer bolts with tubular spacers, so the linkage mounting bracket was in about the same position. It worked for years.

Either by using a kickdown cable or some other way, I'm sure I can engineer a solution if I can't find factory parts.

Maybe someone has enough parts laying around to measure and compare Super Six and non Super Six transmission kickdown levers? I always adjusted mine to have full kickdown lever push-age at wide open throttle or just before.

In the winter, I'd use flexible 4" aluminum dryer duct hose clamped onto 2 header tubes and routed into the air cleaner inlet, with a hole poked in the dryer ducting, to provide heated intake air.
 
volaredon said:
Yup I know that. It's about 10 years before they came out with a super 6. That's why I said I'd have to cut the bottom out of a 318 air cleaner and weld it into the bottom of the "super 225" one to make it work. But I like the looks of the "super 225's" air filter housing better.... I'm also gonna have to pirate the elbow from the 318 housing for the valve cover breather....
Click to expand...
I made the distinction because the OP might not have known. "Super 225" and "Super Six" aren't the same and I wanted to make sure HE knew it. ;)
 
timk225 said:
Way back in 1997-2004 when I had my 1971 Plymouth Valiant all tuned up, first with a BBD and later with a Holley 450 mechanical secondary, I also had Clifford Street Rod headers on the car. My solution for the kickdown linkage was using the stock Super Six linkage and mounting brackets. After some careful measuring, since I no longer had the stock exhaust manifold on the car, I used longer bolts with tubular spacers, so the linkage mounting bracket was in about the same position. It worked for years.

Either by using a kickdown cable or some other way, I'm sure I can engineer a solution if I can't find factory parts.

Maybe someone has enough parts laying around to measure and compare Super Six and non Super Six transmission kickdown levers? I always adjusted mine to have full kickdown lever push-age at wide open throttle or just before.

In the winter, I'd use flexible 4" aluminum dryer duct hose clamped onto 2 header tubes and routed into the air cleaner inlet, with a hole poked in the dryer ducting, to provide heated intake air.
Click to expand...
And it never ran to its full potential. Know why? Because those carburetors are for tunnel rams or dual quad applications only. They are not designed to run single. Though a lot of people have done it, they don't run as well as they could by choosing a "more correct" carburetor. A Holley 390 or Edelbrock 500 are two good examples.
 
There was an air cleaner housing specifically for cars with A/C; it has a flatted area on the front of the housing to (barely) clear the compressor. I don't remember for certain, but the first year Chrysler started using Sanden and Nippondenso round-body compressors on some RWD applications was right around the first year ('77) the Super Six was available; it might be the case that the Super Six cars used those compressors rather than the chonky Chrysler V2/RV2 item.

(There was also an air cleaner housing specifically for Dodge vans with the 225-2bbl; it has an offset base—the carb is not smack in the middle of the baseplate. This, if you can find one, can give ample clearance for whatever A/C compressor you might run).

See this thread for kickdown options.
 
I was working on the car today and realized something. No way will a long ram intake fit. Because my car has power disc brakes, so the carburetor and master cylinder would be trying to occupy the same space. As it is the stock 1 barrel air cleaner only has about 2 inches to the master cylinder for clearance. A Super Six air cleaner is going to be close, and might have to be notched to fit.

73 Duster carburetor clearance.jpg
 
When did you decide to use a "long ram" manifold? The stock super six 2 bbl manifold is the same length as the 1 bbl manifold. It will clear the PB unit.
 
You must log in or register to reply here.
-

Back
Top