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1972 Slant 6 Duster

62K views 33 replies 19 participants last post by  FlaCharger 
#1 ·
I was ready to buy a charger roller and it fell through :blam:. So I found a 1972 slant 6 duster pretty cheap. Has a little bit of rust on the rear quarters and the driver floor pan. I'm trying to research now, but what's the difference between the model with the slant 6 and the v8? I want to turn this into a straight drag car.
 
#4 ·
You'd probably want a 727 trans or similar and a stronger rear end than what comes with the 6. I think body is the same. Having said that, back in the 80's my uncle did up a slant 6 with headers, offenhauser intake, cam, Holley carb and could light up his rear tire for as long as he wanted too. It was pretty cool. You should probably start with V8, 340/360 - just my opinion
 
#11 · (Edited)
I'm a little rusty since I haven't fooled around with A bodies in a while, but I do know that 72 down bolt pattern are the same 4" whether disk or drum. They did have these brakes on both V8 and 6 cylinder. 73 up are more common and there are more wheel options on the 4 1/2" bolt pattern. I think both were the same size brakes but I that I'm not 100% sure on that part since I don't remember.

Also, most people swap the k members since they have the V8 mounts on them already if your swapping in an LA motor, but since this in the resto mod section I'm guessing it's gonna be a hemi. Lol On that note, I don't know if they make a 6 cylinder conversion to Gen III hemi mounts. I know they make 6 to 8 cylinders mounts so I'm guessing they should make them for hemi's too, just never seen them. I know they do for LA to Hemi. TTI makes headers for Gen III hemi in an A body.

The trans is a 904 both made for 6 and 8's. The bell housing is different between them. Last I heard there was some debate which trans was better 904 or 727. I guess the same debate on which Chevy trans is better the TH350 or the TH400. Both the 904 and 727 will bolt to a Gen III Hemi but you can't use the top bolt on the mounts since the hemi doesn't have that bolt hole.

I think the drive shaft was also different between the 904 and 727. The 727 having a longer tail housing than the 904 so the 727 would have a shorter drive shaft.

Torsion bars are definitely different between 6 and 8. 8 being beefier than the 6.

Rear is a 7 1/4 while the bigger rear is the 8 3/4 that you will need.

Oh and Mopar limited slip rears are called Sure Grips not trac-lok or worse Posi. Lol
 
#8 ·
brakes are different too if i recall. It may have front and back drums if its a slant 6.
 
#9 ·
Lil trivia....I think the lug nuts are reverse thread onthe passanger side, not 100%, it been a looong time, but lefty may be tighty.
 
#12 ·
I have a 1972 Duster with a 318. No reverse threads on the wheels, but if it yours has them they are marked on the ends. Not sure when they finally stopped that nonsense.
Also, mine has 4 wheel drums. They suck.
 
#13 ·
I think the reversed threads were used sometime in the 60's
 
#17 ·
All BlackAce said..
Plus disk brake conversions are everywhere.
Reality --
If your going full on race car, everything here discussed is irrelevant.
Yes, the basic frame & sheet metal is the same. But going race car, your looking tube chassis. So then your probably looking at a mustang front suspension setup (common swap) then a rearend, just fab in a 4 link and a Ford 9". Roll cage.
Tube K member, order it with the Gen 3 hemi mounts.

So, the non issues...
Brakes, tortious bars, rear leaf springs, rearend. Driveshaft, engine mounts.... I miss anything?
 
#18 ·
As mentioned, you need to change out the K-frame for a V8. The left threaded lugs went out the window in '70. You'll have to shore up the unibody frame. With big time power, that A-body will twist like a pretzel... Go for a 727 transmission -- they're practically bullet proof.
 
#19 ·
What was the recommended lug nut torque back in the day with these left hand nuts? It was probably pretty low and with today's higher torque numbers of 130 lbs the lug nuts will stay tight even if the wheel upon braking try to loosen them. I still think it's a good idea and many big trucks continued to use them, not sure if they still do.

Sent from my SM-N910T using Tapatalk
 
#21 ·
Never built a car before. This will be the first time and I'm looking to learn and try to do everything myself. I know there will be a lot of work ahead and cursing I'm sure...haha
 
#22 ·
In addition to my 69 Dart race car, I also owned a 1972 340 Duster in the past. I'm positive the car was equipped with an A-727 trans, not the A-904 and it had an 8 3/4 differential, not the smaller 7 1/4. I believe that it also had the 4 1/2 bolt circle of the "B" body cars, not the 4" of the regular "A" body cars, but my memory is a bit rusty on that one. It, for sure, did not have left and right hand thread lug nuts. They were all the same.

Left hand tread went out long before 1970. I had a 62 Plymouth 413 that I raced in stock eliminator. It did not have any left hand thread lug nuts, nor did my 1969 Roadrunner.


Phil
 
#23 ·
I just remembered this...

My 72 had lug bolts, not nuts...

It led to alot of confusion the first time i pulled a wheel.
 
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#27 ·
I'm with building up the slant six. Friend of mine has a Dart GT with the performance package slant six(4 bbl, headers, cam) and even with the Torqueflite , he can almost keep up with my Magnum until 60 mph. I think if he had drag radials, he could whoop me. Sounds awesome to. I've seen a couple built slant sixes with blowers that were screamers. Like to see Engine Masters build one!
 
#30 ·
Good 'ol /6

The /6 ! It's the Leaning Tower of Power!

Hey I think Alston Chassisworks makes cage and suspension kits for that car.

I had a '71 Scamp than ran 10's with a license plate - cops Hated that car! :mrgreen:

View attachment 66590

Have fun with it man, the A bodies actually handle pretty good with a fat motor too.
 
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