'The 383' ~ Getting Those True Factory Horsepower Ratings

[69 Cuda 440]

Mopar 383 ~ 4-Barrel

With Timing Set @ 35* Total Advance

Year ............ Advertised HP ............... True Factory HP

1963 .................. 383 ~ 330 HP .................... 285 HP

1964 .................. 383 ~ 330 HP .................... 285 HP

1965 .................. 383 ~ 330 HP .................... 285 HP

1966 .................. 383 ~ 325 HP .................... 278 HP

1967 .................. 383 ~ 325 HP .................... 278 HP
1967 .................. 383 ~ 280 HP {A-Body} ...... 271 HP

1968 .................. 383 ~ 330 HP ..................... 288 HP
1968 .................. 383 ~ 300 HP {A-Body} ...... 283 HP
1968 .................. 383 ~ 335 HP ..................... 303 HP > {Road Runner / Super Bee}

1969 ................. 383 ~ 330 HP ..................... 288 HP
1969 ................. 383 ~ 330 HP {A-Body} ...... 295 HP
1969 ................. 383 ~ 335 HP ..................... 303 HP > {Road Runner / Super Bee}

1970 ................. 383 ~ 330 HP .................... 288 HP
1970 ................. 383 ~ 335 HP .................... 303 HP > {Road Runner / Super Bee}

1971 ................. 383 ~ 300 HP ..................... 299 HP > {w/Holley Carburetor}

 

[Abodybomber]

Sounds honest,through manifolds.., you tell me ....(Hello..)

 

[69 Cuda 440]

Sounds honest,through manifolds.., you tell me ....(Hello..)

Yes, thru the Stock Exhaust System >

Mopar did claim that you could squeeze out an additional {+6 HP} if you bumped
up timing from 35* to 40* Total Advance.

As for Headers >

Mopar numbers showed a Gain of {+21 HP} over the 'stock' B-Body Exhaust System with a set of 'Hedman' H-DP2 Headers.

And in the {A-Body} with the restricted 'stock' Exhaust System, a set of
Headers unleashed an additional {+26 HP}.

 

[Abodybomber]

Yes, thru the Stock Exhaust System

Mopar did claim that you could squeeze out an additional {+6 HP} if you bumped
up timing from 35* to 40* Total Advance.

It's a start.. I'm sitting back,let others chime in.. ( makes it so much more fun..)..

 

[duster360]

Looks like a couple cheap mods would put the 383 at or a little above the advertised 330 horsepower.

 

[Dartnut]

I think the carbs were too small.

 

[baracus]

There was an article in a mopar mag, can't remember which one but it was within the last few years. They did a stock rebuild and go right at the rated hp, ayone familiar?

 

[69 Cuda 440]

I think the carbs were too small.

That would be correct.

Mopar had tested the 383 with an Edelbrock {#DP-4B} Dual-Plane High Rise and with a Holley 780 CFM {Vacuum Secondary} Carburetor.

They found an increase in Horsepower of {+22 HP} @ 4800 RPM's.

 

[fratzog lover]

http://www.hotrod.com/how-to/engine/mopp-0209-383-engine-restore/



This one?

 

[baracus]

That's it thanks. So... happy dyno? Good machine work?

 

[69 Cuda 440]

NHRA Numbers

* 1963 ...... 383-330 HP ................ 280 HP
* 1964 ...... 383-330 HP ................ 280 HP
* 1965 ...... 383-330 HP ................ 280 HP
* 1966 ...... 383-325 HP ................ 280 HP
* 1967 ...... 383-325 HP ................ 280 HP
* 1967 ...... 383-280 HP {A-Body} .. 280 HP

* 1968 ..... 383-330 HP ................. 295 HP
* 1968 ..... 383-300 HP {A-Body} ... 294 HP
* 1968 ..... 383-335 HP ................. 300 HP > {Road Runner / Super Bee}

 

[69 Cuda 440]

Nik-Nak,

Be advised, that the 1963, 1964 and 1965 - 383/330 HP Engines came thru with
a different Camshaft.

These were the same Camshafts found in the 1964 and 1965 - 426/365 HP
'Street-Wedge'

Lift ............. .431"/.431"
Duration ...... 268*/268*
Overlap ....... 48*
--------------------------------------------------------------------------------------

In 1966, Mopar lowered the 383 to 325 HP and changed the Camshaft >

Lift ............. .425"/.437"
Duration ...... 256*/260*
Overlap ....... 32*
---------------------------------------------------------------------------------------

In 1968 the 'new' 383/335 HP {Road Runner / Super Bee} Camshaft

Lift ............. 450"/.458"
Duration ..... 268*/284*
Overlap ....... 46*
---------------------------------------------------------------------------------------

Back Information >

Originally, the 383 'Road Runner' Camshaft was supposed to have these 'specs'.

Lift ........... .450"/.465"
Duration .... 276*/292*
Overlap ..... 54*

 

[fratzog lover]

Seems like 5 hp at mopar was always different than 5 hp in my garage. At least with the road runner engine!

 

[69 Cuda 440]

Hard to Imagine

That the 1968 383/335 HP {Road Runner / Super Bee} Engine put out only
{+10 HP} over the 1966 and 1967 383/325 HP.

That was pretty funny.

Better Cylinder Heads
Larger Exhaust Valves
Better Flowing Exhaust Manifolds
Larger Exhaust Manifold Header Outlet
More Aggressive Camshaft
Higher Load-Rate Valve Springs
Improved Flowing Intake Manifold
Carter AVS {630 CFM} vs. Carter AFB {566 CFM}
Windage Tray

 

[fratzog lover]

That was what I was talking about. I also didnt know about the 1966 cam change.

 

[69 Cuda 440]

That was what I was talking about. I also didnt know about the 1966 cam change.

Camshafts

The 1963, 1964 and 1965 - 383/330 HP Camshaft was the 'same' Camshaft as
the 1964 and 1965 - 426/365 HP 'Street Wedge'.

 

[69 Cuda 440]

Nik-Nak,

Be advised, that the 1963, 1964 and 1965 - 383/330 HP Engines came thru with
a different Camshaft.

These were the same Camshafts found in the 1964 and 1965 - 426/365 HP
'Street-Wedge'

Lift ............. .431"/.431"
Duration ...... 268*/268*
Overlap ....... 48*
--------------------------------------------------------------------------------------

In 1966, Mopar lowered the 383 to 325 HP and changed the Camshaft >

Lift ............. .425"/.437"
Duration ...... 256*/260*
Overlap ....... 32*
---------------------------------------------------------------------------------------

In 1968 the 'new' 383/335 HP {Road Runner / Super Bee} Camshaft, which
was the same as 440 'Super Commando' and' Magnum 440'

Lift ............. 450"/.458"
Duration ..... 268*/284*
Overlap ....... 46*
---------------------------------------------------------------------------------------

Back Information >

Originally, the 383 'Road Runner' was supposed to have it's own
special bumpstick with these 'specs' >

Lift ........... .450"/.465"
Duration .... 276*/292*
Overlap ..... 54*

And in mid-1968, Mopar almost 'pulled-the-trigger' on a 383 Super High Performance Package.

Components
* TRW 11.0-1 Forged Pistons
* Edelbrock Aluminum Dual-Plane High-Rise Intake Manifold
* Holley 780 CFM Carburetor
* Camshaft #3412004
* High Load-Rate Valve Springs

Lift............ .484"/.484"
Duration..... 284*/284*
Overlap...... 68*
LSA .......... 108*


That is correct.........

 

[mikedevore]

Would have liked to see that 383 performance package make it to production.
Any idea on power numbers from that combo?

 

[YY1]

That's why the 284/484 works so well in these!

 

[EL5DEMON340]

From most of the guys I talk to, even GM guys the the 383-335HP RR/bee's were quicker than the 396 325hp and the in most cases the 350hp also. The 375hp 396 would kick it's butt pretty good.

 

[69 Cuda 440]

Would have liked to see that 383 performance package make it to production.
Any idea on power numbers from that combo?

Mike,

On the 1968 - 383 Super High Performance Package. It was for the Road Runner 'only'

Was supposed to be a mid-year 'option', once the Hardtop Models came out.
Mopar had also changed from the 'Inland Shifter' to the Hurst Shifter.

And it was supposed to be made available with 4.10 Gears in the 4-Speed,
and 3.91 Gears in the Automatic.

And, mandatory 15" Magnum Road-Rallye Wheels with G-70 x 15" Tires.

Believe It Or Not >

The Plymouth GTX 'Sales and Marketing Department' shot it down........

 

[fratzog lover]

What a surprise, the top dog is protected again. GM was noted for that.

 

[69 Cuda 440]

What a surprise, the top dog is protected again. GM was noted for that.

In mid-1968 {Sales Year}

Plymouth Sales and Marketing {Road Runner Group} wanted to target the
mid-year 1968 Pontiac GTO with the 400/360 HP 'HO' Engine.

 

[mikedevore]

In mid-1968 {Sales Year}

Plymouth Sales and Marketing {Road Runner Group} wanted to target the
mid-year 1968 Pontiac GTO with the 400/360 HP 'HO' Engine.

This would have been a good way to do that.

It is amazing on what individual groups in a corporation do to protect each other instead of whats good for the company as a whole.

I would have thought the GTX buyer would have still bought the GTX over a hot rod Road Runner, given the choice.

 

[69 Cuda 440]

This would have been a good way to do that.

It is amazing on what individual groups in a corporation do to protect each other instead of whats good for the company as a whole.

I would have thought the GTX buyer would have still bought the GTX over a hot rod Road Runner, given the choice.

In House Competition at Plymouth for the 1968 Sales Year >

The GTX Sales and Marketing Group were fearful that a 'stripped down'
1968 Road Runner with a 383 Special High Performance with 360 Horsepower
would have derailed the sales of the GTX 440.