Factory HP ratings: 1967 383 versus 1968/1969 383

[440 Cuda]

1967

* 383/325 HP ........ Plymouth 'Super Commando 383'
* 383/280 HP ........ Barracuda 383-S 'Commando 383'

* 383/325 HP ........ Dodge B-Body '383 Four-Barrel'
* 383/280 HP ........ Dart GTS 383 '383 Four-Barrel'

Dyno Tests had the 383/325 HP running closer to 290 HP.

In the A-Body, with the restrictive exhaust, the 383 put out 278 HP.

* Compression Ratio........ 10.0 - 1
* Piston.......................... Flat Top
* Piston Height................ -.014"

 

[monaco66coupe]

thanks 440 cuda, Bone stock was .425/.435 and 256-260 with 32 degrees overlap. Same specs as the 426. I'm not up on class designation, . was that Bone stock class?

 

[440 Cuda]

1967 '383'

Camshaft 'Hydraulic'
.425" / .437" Lift ~ 256* / 260* Duration ~ 32* Overlap

Valve Springs
#134 lbs. {Valve Closed} ~ #208 lbs. {Valve Closed}

Intake Manifold
#301 666 968

- - - Updated - - -

Carter 'AFB' Carburetor {575 CFM}

383/325 HP ~ {Plymouth and Dodge 'B-Body'}
#4298 {Manual} ~ #4299 {Automatic}
Throttle = 1.437" x 1.563"
Venturi = 1.186" x 1.313"

383/280 HP ~ {Barracuda 383}
#4298 {Manual} ~ #4299 {Automatic}
Throttle = 1.437" x 1.563"
Venturi = 1.186" x 1.313"

383/280 HP ~ {Dart GTS 383}
#4309 {Manual} ~ #4310 {Automatic}
Throttle = 1.437" x 1.563"
Venturi = 1.063" x 1.563"

 

[440 Cuda]

Comparing the 1967 {383/325 HP} versus the 1968/1969 {383}.

For one, the 383/325 HP was way 'over-rated'

Back in 1967 we came up with 280 to 285 HP @ 4800 RPMs on the Dyno at our Performance Center.

And the 1967 '383' in the A-Body was only putting out 275 HP @ 4200 RPM's.

 

[440 Cuda]

1967................. Dyno HP
* 383/325 HP ... {278 HP} ... B-Body {Belvedere, Satellite, Coronet and Charger}
* 383/280 HP ... {270 HP} ... A-Body {Barracuda 383-S and Dart GTS 383}

1968................. Dyno HP
* 383/335 HP ... {306 HP} ... Road Runner and Super Bee
* 383/330 HP ... {288 HP} ... B-Body {Belvedere, Satellite, Coronet and Charger}
* 383/300 HP ... {284 HP} ... A-Body {Barracuda 383-S and Dart GTS 383}

 

[440 Cuda]

The 1967 383 4V in my Coronet wagon is rated by the factory at 325HP with dual exhaust, which it has. The 1968/1969 383 in the Roadrunner was rated at 335HP, only 10 HP more, even though it had a better cam, better exhaust manifolds, and I would think a more performance oriented carb?

My 1967 383 has the 516 heads, which I understand are less desirable than the 915 heads. Additionally, it does not have the HP exhaust manifolds, which I believe came with the Roadrunner.

So my question is why only a difference of 10HP from 1967 to 1968/1969? Did the 906 heads take away some of the performance gains from the other improvements? If so, how much would an otherwise stock 1968/1969 383 have benefited from the 915 heads? Or, at lower HP levels did the changes/differences not have that much of an impact?

Granted, aluminum heads are definitely the way to go today -- I'm just trying to educate myself.

If this has already been discussed in another thread, feel free to point me in that direction; I looked around quite a bit and didn't find anything that addressed this.

Thanks for any information on this!

Chris
Sacramento, CA

Chris,

You can't go by Mopar's 'advertised horsepower numbers'.

The 383/325 HP {1966 and 1967} was over-rated.

True 'Horsepower Numbers' for the {383/325 HP} came in at 278 HP for the 383 4-Barrel.

 

[440 Cuda]

Hot Rod Magazine {October 1967}

383/325 HP

Engine Dyno = 278 HP

http://i.ebayimg.com/00/s/MTA5Nlg4MDA=/$(KGrHqZHJE8E-vgrh--tBP4ez20IVg~~60_57.JPG

Engine Specs

* Compression........ 10.0 - 1
* Piston.................. Flat Top
* Piston Height........ {-.014" } Below Deck

* Camshaft {Hydraulic}
* Lift...................... .425"/.437"
* Duration............... 256*/260*
* Overlap................ 32*

* Intake Manifold {#301 666 968}
* Cast Iron / Low-Rise
* Dual-Plane

* Carburetor {Carter AFB}
* CFM Rating.......... 575
* Throttle Sizes....... 1.437" x 1.563"
* Venturi Sizes........ 1.186" x 1.313"

* Cylinder Head {#2506516}
* Combustion Chamber... Closed
* CC Level.................... 79.5 {Factory}
* CC Level {Minimum}... 73.5
* Intake Valve............... 2.08"
* Exhaust Valve............. 1.60"
* Valve Springs............. Single-Coil
* Load Rate.................. #134 lbs. {Valve-Closed} / #208 lbs. {Valve Open}
* Gasket Thickness........ .021"

* Exhaust {Dual}
* Primary Pipe............. 2.25"
* Tail Pipe................... 2.25"

 

[moparlouie]

This should be worth about another foot of comments on this page! My brothers 65 383 Coronet screemed with his 330 HP version! Also ate up the GTO's, and especially thiose boat anker 409's!

 

[1966satellite]

I have a 64 383 that is stamped HP.

 

[monaco66coupe]

I have a 64 383 that is stamped HP.View attachment 191712

My brother also laughed , when I mentioned the topic of overrated 383's ! He raced the 383(64-68) back then, and those dyno reports are considered bogus by him as well. Cliff said if they were overrated, they were the fastest overrated cars out there! On the street, the 383 was a real competitor. I have a friend that was part of a race team supported by Chrysler,(67-73) and he said the fastest guys weren't on the track. The fastest guys frequently couldn't have cared less about racing on the track. Guys with money were found on the track, not necessarily the most talented drivers out there. To many The streets were much more exciting. I found it a lot like car shows, the guys there think their cars are the primo's of the era. When in actuality, The nicest cars are frequently in someone's garage, and owned by somebody that doesn't like showing his car.

 

[monaco66coupe]

Another perspective was recently shared with me by several old racer guys from back then: Hotrod magazine and car and driver leaned heavily ,about 70% towards GM, 20% Ford, and 10% Mopar. The never had anything good to say about mopars in those magazines, and few of them had the money to actually pull an engine out of a new car and test it at the crank. They would run the test by at the rear wheels, and extrapolate to come up with whatever they thought would sound good. And when it came time to test the cars at the track, they had a goof ball with a stop watch at the 1/4 mile, and a goofball driving. and, the same cars were often rotated around the different magazines. I saw it frequently in the motorcycle magazines of the early 70's, where the mag admitted the manufacturer had brought the subject bike from another recent magazine test. I have watched many car shows where a dyno guy is playing with a chevy, and having a hell of a time even getting near the factory rating, but nobody rags on them for being overrated. Not all dyno guys are created equal, and as it goes in any trade. I can say I never subscribed to Hotrod back then, as the magazine was, in my opinion, biased and outright hostile and derogatory to mopars a majority of the time. Which is why Mopar magazines began to show up on the stands.

Thank God for Mopar muscle, mopar collectors guide, and all the others that try to bring a more accurate picture of the Mopar brand.

 

[theman440]

My lowly "278hp" 383 4bbl Coronet hauls the mail!

 

[440 Cuda]

No Disrepsect to the 383,

But as a a Mopar Guy, those mid 1960's 383 didn't scare anybody.

They were a good durable Big Block, that could run forever.

And in 1968, the 383/335 HP Road Runner and Super Bee were demolished in E/S and E/SA.

 

[440 Cuda]

1967
Factory Advertised.... Dyno
* 383/280 HP .............. 270 HP
* 383/325 HP............... 278 HP

1968
Factory Advertised.... Dyno
383/300 HP.................. 284 HP
383/330 HP.................. 288 HP
383/335 HP.................. 306 HP

 

[440 Cuda]

..........................1967 Engine Specs................. 1968 Engine Specs............. Road Runner/Super Bee

* Engine.................... 383/325 HP............................ 383/330 HP ..................... 383/335 HP

* Engine Dyno ............ 278 HP ................................. 288 HP ........................... 310 HP

* Compression............ 10.0 - 1 ................................ 10.0 - 1 .......................... 10.0 - 1
* Piston..................... Flat Top ................................ Flat Top ........................... Flat Top
* Piston Height.......... {-.014" } Below Deck ............. {+.021" } Above Deck ....... {+.021"} Above Deck

* Camshaft............... {Hydraulic} .......................... {Hydraulic} ....................... Hydraulic
* Lift........................ .425"/.437" .......................... .425"/.437" ...................... .450"/.458"
* Duration................. 256*/260* ........................... 256*/260* ....................... 268*/284*
* Overlap.................. 32* ..................................... 32* ................................. 46*

* Intake Manifold...... {#301 666 968} .................. {#2806301} ....................... {#2806301}
* Type..................... Cast Iron.............................. Cast Iron ............................ Cast Iron
* Style .................... Dual-Plane............................ Dual-Plane ......................... Dual-Plane
* Height................... Low-Rise.............................. Medium-Rise ...................... Medium-Rise

* Carburetor................{Carter AFB} ...................... {Carter AVS} .................... {Carter AVS}
* CFM Rating............... 575 .................................... 625 ................................. 625
* Throttle Sizes............ 1.437" x 1.563" ................... 1.437" x 1.688" ............... 1.437" x 1.688"
* Venturi Sizes............. 1.186" x 1.313" ................... 1.186" x AV ..................... 1.186" x AV

* Cylinder Head........... {#2506516} ....................... {#2843906} .................... {#2843906}
* Combustion Chamber. {Closed}............................. {Open} ........................... {Open}
* CC Level {Factory}......79.5 .................................. 88.0 ................................ 88.0
* CC Level {Minimum}... 73.5 .................................. 79.5 ............................... 79.5
* Intake Valve............... 2.08" ................................ 2.08"............................... 2.08"
* Exhaust Valve............. 1.60" ................................ 1.74" .............................. 1.74"
* Valve Springs............. Single-Coil.......................... Single-Coil ...................... Single-Coil w/Damper
* Load Rate.................. #134 lbs. {Valve-Closed}.... #134 lbs. {Valve-Closed} ... #134 lbs. {Valve-Closed}
* Load Rate.................. #208 lbs. {Valve-Open}...... #208 lbs. {Valve-Open} ..... #256 lbs. {Valve-Open}
* Gasket Thickness........ .021" ............................... .020" ................................ .020"

* Exhaust ................... {Dual} ............................. {Dual}............................. {Dual}
* Primary Pipe............... 2.25" ............................... 2.25" ............................... 2.50"
* Tail Pipe..................... 2.00" ............................... 2.00" ................................2.25"[/QUOTE]

 

[Garys1969RR]

Although the 383 horsepower ratings were inflated from the factory, I still loved the roar when you pushed the throttle wide open. My best friends Mom had a 65 Fury III convertible with a 383 Commando, and we fell in love with that car! So when the Roadrunner came out in 1968 with the 383 as the standard engine, I had to have one. That started my career as a Mopar man. I can remember my friends Mom putting around town in her Fury, and when she went around a curve the oil light would come on! Checked the oil and it was like 3 quarts low! Added oil then it ran fine for years. Made many trips between Kansas City and Denver at 90 to 100 MPH and kept on going.

 

[HawkRod]

One other thing to consider here:

My father-in-law, an engine builder by trade, says that original factory Mopar engines are very variable. Many were not very "square" or machined very well from the factory. So taking any 383 off the assembly line and testing it was probably subject to a lot of error depending on if you got a good one. A properly machined and blueprinted 383 runs very well, but I am sure there are quite a few dogs out there too...

 

[Garys1969RR]

I remember Mopar Muscle magazine doing a blueprint and re build on a 383 a year or 2 back, and came up with about 335 horsepower or a bit more. They used adjustable rocker arms, and a little more cam than the stock one. And they did a good valve job on it. Does any one have the link to that article? Seems like it was around October 2013.

 

[440 Cuda]

..........................1967 Engine Specs................. 1968 Engine Specs

* Engine.................... 383/325 HP............................ 383/330 HP

* Engine Dyno ............ 278 HP ................................. 288 HP

* Compression............ 10.0 - 1 ................................ 10.0 - 1
* Piston..................... Flat Top ................................ Flat Top
* Piston Height.......... {-.014" } Below Deck ............. {+.021" } Above Deck

* Camshaft............... {Hydraulic} .......................... {Hydraulic}
* Lift........................ .425"/.437" .......................... .425"/.437"
* Duration................. 256*/260* ........................... 256*/260*
* Overlap.................. 32* ..................................... 32*

* Intake Manifold...... {#301 666 968} .................. {#2806301}
* Type..................... Cast Iron.............................. Cast Iron
* Style .................... Dual-Plane............................ Dual-Plane
* Height................... Low-Rise.............................. Medium-Rise

* Carburetor................{Carter AFB} ...................... {Carter AVS}
* CFM Rating............... 575 .................................... 625
* Throttle Sizes............ 1.437" x 1.563" ................... 1.437" x 1.688"
* Venturi Sizes............. 1.186" x 1.313" ................... 1.186" x AV

* Cylinder Head........... {#2506516} ....................... {#2843906}
* Combustion Chamber. {Closed}............................. {Open}
* CC Level {Factory}......79.5 .................................. 88.0
* CC Level {Minimum}... 73.5 .................................. 79.5
* Intake Valve............... 2.08" ................................ 2.08"
* Exhaust Valve............. 1.60" ................................ 1.74"
* Valve Springs............. Single-Coil.......................... Single-Coil
* Load Rate.................. #134 lbs. {Valve-Closed}.... #134 lbs. {Valve-Closed}
* Load Rate.................. #208 lbs. {Valve-Open}...... #208 lbs. {Valve-Open}
* Gasket Thickness........ .021" ............................... .020"

* Exhaust {Dual}
* Primary Pipe............... 2.25" ............................... 2.25"
* Tail Pipe..................... 2.25" ............................... 2.25"

[/QUOTE]

Comparison between the 1967 {383/325 4-Barrel} and 1968 {383/330 HP 4-Barrel}.

Dyno Tests,

The #2843906 Cylinder Head put out {+5 HP} over the #2506516 Cylinder Head, when installed on the basic 383 4-Barrel
at 4600 RPM's.

The #2806301 Intake Manifold and Carter AVS {625 CFM} put out {+5 HP} over the #301 666 968 Intake Manifold and
Carter AFB {575 CFM} when installed on a basic 383 4-Barrel at 4600 RPM's.

 

[440 Cuda]

1967 '383' versus 1968 '383'

................................ 1967 B-Body ........................ 1968 B-Body .................. 1968 Road Runner/Super Bee

* Engine.................... 383/325 HP............................ 383/330 HP ..................... 383/335 HP

* Engine Dyno ............ 278 HP ................................. 288 HP ........................... 310 HP

* Compression............ 10.0 - 1 ................................ 10.0 - 1 .......................... 10.0 - 1
* Piston..................... Flat Top ................................ Flat Top ........................... Flat Top
* Piston Height.......... {-.014" } Below Deck ............. {+.021" } Above Deck ....... {+.021"} Above Deck

* Camshaft............... {Hydraulic} .......................... {Hydraulic} ....................... Hydraulic
* Lift........................ .425"/.437" .......................... .425"/.437" ...................... .450"/.458"
* Duration................. 256*/260* ........................... 256*/260* ....................... 268*/284*
* Overlap.................. 32* ..................................... 32* ................................. 46*

* Intake Manifold...... {#301 666 968} .................. {#2806301} ....................... {#2806301}
* Type..................... Cast Iron.............................. Cast Iron ............................ Cast Iron
* Style .................... Dual-Plane............................ Dual-Plane ......................... Dual-Plane
* Profile................... Low-Rise............................... Low/Medium-Rise ................ Low/Medium-Rise
* Carb Pad Height..... 3.13"................................... 3.44" ................................. 3.44"

* Carburetor................{Carter AFB} ...................... {Carter AVS} .................... {Carter AVS}
* CFM Rating............... 575 .................................... 625 ................................. 625
* Throttle Sizes............ 1.437" x 1.563" ................... 1.437" x 1.688" ............... 1.437" x 1.688"
* Venturi Sizes............. 1.186" x 1.313" ................... 1.186" x AV ..................... 1.186" x AV

* Cylinder Head........... {#2506516} ....................... {#2843906} .................... {#2843906}
* Combustion Chamber. {Closed}............................. {Open} ........................... {Open}
* CC Level {Factory}......79.5 .................................. 88.0 ................................ 88.0
* CC Level {Minimum}... 73.5 .................................. 79.5 ............................... 79.5
* Intake Valve............... 2.08" ................................ 2.08"............................... 2.08"
* Exhaust Valve............. 1.60" ................................ 1.74" .............................. 1.74"
* Valve Springs............. Single-Coil.......................... Single-Coil ...................... Single-Coil w/Damper
* Load Rate.................. #134 lbs. {Valve-Closed}.... #134 lbs. {Valve-Closed} ... #134 lbs. {Valve-Closed}
* Load Rate.................. #208 lbs. {Valve-Open}...... #208 lbs. {Valve-Open} ..... #256 lbs. {Valve-Open}
* Gasket Thickness........ .021" ............................... .020" ................................ .020"

* Exhaust ................... {Dual} ............................. {Dual}............................. {Dual}
* Primary Pipe............... 2.25" ............................... 2.25" ............................... 2.50"
* Tail Pipe..................... 2.00" ............................... 2.00" ................................2.25"

[/QUOTE]

Specifications............