'Match Race' ~ 1968 Barracuda '340-S' vs. 1971 'Duster 340'

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69 Cuda 440

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Match Race between the 340's

1968 Barracuda '340-S' ~ 4-Speed

* 10.5-1 Compression
* 'X-Head' #2531894 = 2.02" Intake ~ 1.60" Exhaust

* Camshaft = .464"/.468" Lift ~ 284*/292* Duration ~ 60* Overlap

* Cast Iron Intake #2531915
* Carter AVS 625 CFM = {1 7/16"Primary x 1 11/16" Secondary}


1971 'Duster 340' ~ 4-Speed
* 10.3-1 Compression
* 'J-Head' #3418915 = 2.02" Intake ~ 1.60" Exhaust

* Camshaft = .429"/.444" Lift ~ 268*/276* Duration ~ 44* Overlap

* Cast Iron Intake #3512100
* Carter Thermoquad 800 CFM = {1 3/8" Primary x 2 1/4" Secondary}
 
The 340 in the duster appears to be at a loss in comparison to the 340 in the barracuda, though the TQ would have a significant advantage as the motor winds up.

I also recall 1971 reputably being one of the best years for the factory 340 motor...
 
I was lucky enough to drive 'Stock 340' A-Body Mopars from 1968 thru 1973.

The 'Camshaft' in the 1968 340 4-Speed was 'The Real Deal', and it pushed those Valve Springs
{235 lbs. w/Valve Open} to their limit.

I would have to say though, that the Carter AVS 625 CFM {though a good street Carburetor}
limited optimal performance on Top End.

The 1971 340, with that 'Monster' Thermoquad 800 CFM was a 'Uni-Vac' on the big end, and once
that Engine started to Rev,,,,,,,,,watch out.
 
1968 Barracuda 340 'Formula S'

* 340/275 HP

The Fastback {#3162 lbs. = Shipping Weight}
4-Speed cars were available with > 3.23 - 3.55 - 3.91 Gears 'Sure-Grip'

Typically found with Manual Steering and 10" Drum Brakes.

778_21_low_res.jpeg
 
I'll take one of each, please.
 
This would be a very close race. Bigger cam with a smaller carb versus a smaller cam with a bigger carb. Fuel flow about the same? Compression difference is negligible? Would the stock tires make a difference? AM radio versus AM/FM?
 
1971 'Duster 340'

Comes in at #3140 lbs.

In 1971, Drum Brakes and Manual Steering > 'Standard Equipment'.

But most 1971 Duster 340's came equipped with Power Steering and
Front Disc Brakes, adding approximately 40 lbs. on the nose.

So weight was pretty much a 'Toss Up'.............
 
DFX 340 Duster said:
This would be a very close race. Bigger cam with a smaller carb versus a smaller cam with a bigger carb. Fuel flow about the same? Compression difference is negligible? Would the stock tires make a difference? AM radio versus AM/FM?
Click to expand...

I think the AM/FM radio option just might be the most important factor here lol

All kidding aside, what gearing was typically found in the duster? Was 3.91 an option?

The tire sizes offered and the availability of a sure-grip would be key as well, thought I believe both cars were available with factory sure-grip differentials. I wonder if cone or clutch style sure-grips would make any difference at the strip...:happy1:
 
Seeing the cam options these are both 4 spd. and yes they were both available with 391's. I had both but the 68 was a dart. The 71 would pull on the top like a freight train. I would like to see the actual numbers from back then on this match up.
 
The big t quad, and the better intake manifold makes the 71 quicker. And the best year HP wise for the 340.
 
1971 'Duster 340'

In 1971,
> The typical standard 'Dealer Stocking Cars' left the Factory with 3.23 Gears and 'Sure-Grip'.
> Power Steering and Front Disc-Brakes.
> AM Radio
> Rallye Wheels w/E-70 x 14" Goodyear Polyglas GT 'R-W-L'

It didn't matter whether it was a 4-Speed or Automatic.
 
Would have been nice if they used the 68 cam in all the 340's but then they would be kicking the 440's so I think it was by design they had a mild cam
 
71 Duster 340 / 71 Demon 340 every time....fastest of the A body small blocks.....
 
Id go with the 68. I think the 68 had better compression than any 71 and the 625 would suffice through the traps. The 68 also had better exhaust from the factory. I think a 68 Dart would be lighter still. I had a 68 340 (TQ though) in my '65 and would regularly tangle with a neighborhood 340 duster. Got him every time but I was probably 300 lbs lighter.
 
1968 Barracuda 340 'Formula S'

Performance Results >

In September 1967 , a new 1968 Barracuda 4-Speed Fastback w/3.55 Gears was brought
to the 1967 NHRA Indy Nationals during Prep Week.

The 'test' Barracuda ran 14.35's @ 97 MPH with E-70 x 14" Tires with Plymouth Racing Tech
- Jerry Gross driving.

After some Clutch Adjustments, Carb Tweaking, Advanced Timing by the Chrysler Racing Techs
and 'over-inflated' Front Tires.

They hit a low of > 14.17 @ 98.0 MPH

Note; In the process, they destroyed the 'Inland Shifter' and ruined the Clutch Assembly.
 
73 Swinger,

The Clutch Assembly Units were the same.

#2266232 ~ {10 1/2" Clutch Disc} ~ w/10 Springs {5 Green and 5 Tan}

#2409688 ~ {10 1/2" Pressure Plate} ~ 'Borg & Beck' 3-Finger ~ w/12 Springs {6 White and 6 Tan}
 
I think the 68 Barracuda Notchback 340 4 speed would be faster than the 71 Duster.
 
Shipping Weights

1968 Barracuda {Notchback}....... #3074 lbs.
1968 Barracuda {Fastback}......... #3162 lbs.
1968 Barracuda {Convertible}..... #3198 lbs.

1971 Duster 340.......................... #3140 lbs.
 
Motor Trend {January 1968}

1968 Barracuda 340 'Formula S' ~ 4-Speed ~ w/3.23 Gears
> 15.20 @ 92.0 MPH

This one was questioned.........

mpMA0GxErGSNqSr4v8d_9Mg.jpg
 
did not read it, but most likely the Fastback test. Not much done on the notchbacks 340 4 speed with the 3.91 gears
 
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