1968 Road Runner '383' vs. 1968 Competition

[Abodybomber]

2 more 'sleepers'.

1968 Chevelle Malibu 'Sport Coupe' with the 327/325 HP 'L-79'
Note; {4-Speed only cars}

#3310 lbs. = 10.18 Wt/HP
---------------------------------------------------------------------------

1968 Pontiac Lemans ~ 350 H.O. {350/320 HP}[/I
# 3287 lbs. = 10.26 Wt/HP

Oh geez.. Missed the L-79 option. With the low end Chevelle ,a q ship to be dealt with.
Did that Lemans option ,ever actually exist????. I know Delorean hated that combination.
As for nasty camshafts & overlap,that .474 Olds grind is nasty on overlap. (Near 75-80 degrees,IIRC)...

 

[69 Cuda 440]

A-Body-Bomber,

Yes, the 1968 Pontiac Lemans did come through with a 350/320 HP 'High Output'.

I'll see if I can print up the article from 1968.

In late-1967, the Pontiac Techs in Michigan had gotten a 'new' 1968 Road Runner 383, and ran it thru
some tests to see what the 'actual' performance numbers were.

Reports of 14.85 @ 94 MPH were out there for the Road Runner.

The Pontiac Group then put out the Lemans 350 'HO', which was about {-160 lbs.} lighter than the
Road Runner 383, and was equal in 'sticker price'.

It was to combat the 'low price' of the Road Runner.

Proving Grounds Test
According to the Pontiac Techs, the lightweight Lemans {properly tweaked} and with 3.90 Gears, put
away the Road Runner 383.

'A Plain Jane'

 

[69 Cuda 440]

Stock Camshaft Comparison


Mopar 383/335 HP .................... .450"/458" ........... 268*/284* ....... 46* ........ 115*

Chevrolet 396/350 HP ............... .461"/.480" .......... 300*/300*........ 72* ....... 115*

Chevrolet 327/325 HP ................ 447"/.447" .......... 306*/306* ....... 78* ...... 114*

Buick 400/340 HP ...................... .419"/.449".......... 260*/276* ........ 54*....... 113*

Oldsmobile 400/350 HP ............. .472"/.472" ......... 286*/286* ........ 58* ...... 115*

Oldsmobile 350/325 HP ............. .474"/.474" ......... 308*/308* ........ 86* ...... 115*

Pontiac 400/350 HP ................... .421"/.421" ......... 273*/289* ........ 54* ...... 113*

Pontiac 350/320 HP .................. .421"/.424" .......... 288*/302* ........ 63* ...... 116*

Ford 390/325 HP ........................ 481"/.490" .......... 270*/290* ........ 46* ...... 115*

Mercury 390/325 HP .................. .481"/.490" ......... 270*/290* ........ 46* ...... 115*

American Motors 390/315 HP .... .425"/.425" ......... 266*/266* ........ 44* ...... 112*

Check out that 1968 Oldsmobile 350 'Ram Rod'.

 

[69 Cuda 440]

Back in the Day, popular 'Street' Camshaft upgrades for the 1968 '383' Mopar
___________________________________________________________

* Stock '383 Road Runner'.......... .450"/.458" ~ 268*/284* ~ 46* ~ 115*

* Mopar Street Hemi Grind ......... .474"/.474" ~ 280*/280* ~ 60* ~ 110*

* Racer Brown 'SSH-24'.............. .480"/.480" ~ 280*/280* ~ 52* ~ 110*

* Crower '280' ............................ 475"/.475" ~ 280*/280* ~ 60* ~ 110*

* Mopar '284' ............................. 484"/.484" ~ 284*/284* ~ 68* ~ 108*

* Iskenderian '310'.................... .440"/.440" ~ 310*/310* ~ 74* ~ 114*

 

[69 Cuda 440]

Engine Specifications

............................................ Compression.....Horsepower........Torque..............NHRA Horsepower Rating


Mopar 383/335 HP ...... ........ 10.00-1 ........ 335 @ 5200 ........ 425 @ 3400 ............. 295 HP

Chevrolet 396/350 HP .......... 10.25-1 ........ 350 @ 5800 ....... 415 @ 3400 ............. 340 HP

Chevrolet 327/325 HP .......... 11.00-1 ........ 325 @ 5800 ....... 360 @ 3600 ............. 300 HP

Buick 400/340 HP ................. 10.25-1 ........ 340 @ 5000 ...... 445 @ 3000

Oldsmobile 400/350 HP ....... 10.50-1 ......... 350 @ 5000 ...... 440 @ 3600

Oldsmobile 350/325 HP ....... 10.50-1 ......... 325 @ 5400 ...... 360 @ 3600 .............. 315 HP

Pontiac 400/350 HP ............ 10.75-1 ......... 350 @ 5000 ....... 445 @ 3400 ............. 325 HP

Pontiac 350/320 HP ............ 10.50-1 .......... 320 @ 5100 ....... 380 @ 3200

Ford 390/325 HP ................ 10.50-1 .......... 325 @ 4800 ........ 425 @ 4200 ........... 315 HP

AMC 390/315 HP ................ 10.20-1 .......... 315 @ 4600 ........ 425 @ 3200 ............ 300 HP

 

[Abodybomber]

Thanks.. Compression & overlap,were the keys without head porting.... That doesn't apply ,to the post. It opens up,the possibilities....

 

[69 Cuda 440]

Thanks.. Compression & overlap,were the keys without head porting.... That doesn't apply ,to the post. It opens up,the possibilities....

A-Body,

Correct

The Mopar 383/335 HP {440 Camshaft}, though good as a general performance
bumpstick, really held back the engine.

Those early [Part #3412004] Dealer {484/284} 'over-the-counter' Camshafts had a nice overlap
at 68* and 108* Centerline.

It was good for an additional +20 HP.

The later profile Camshafts [Part #5007697] had a 56* Overlap and 114* Centerline.

 

[69 Cuda 440]

Misconception,

The 1968, Road Runner 383 and Super Bee 383.

'Did not' have the complete 440 Exhaust System.

For 2 Bits, who can answer this 'trick' question.

What exhaust system did the 1968 383/335 HP have ?

 

[69 Cuda 440]

Stock Camshaft Comparison


Mopar 383/335 HP .................... .450"/458" ........... 268*/284* ....... 46* ........ 115*

Chevrolet 396/350 HP ............... .461"/.480" .......... 300*/300*........ 72* ....... 115*

Chevrolet 327/325 HP ................ 447"/.447" .......... 306*/306* ....... 78* ...... 114*

Buick 400/340 HP ...................... .419"/.449".......... 260*/276* ........ 54*....... 113*

Oldsmobile 400/350 HP ............. .472"/.472" ......... 286*/286* ........ 58* ...... 115*

Oldsmobile 350/325 HP ............. .474"/.474" ......... 308*/308* ........ 86* ...... 115*

Pontiac 400/350 HP ................... .421"/.421" ......... 273*/289* ........ 54* ...... 112*

Pontiac 350/320 HP .................. .421"/.424" .......... 288*/302* ........ 63* ...... 116*

Ford 390/325 HP ........................ 481"/.490" .......... 270*/290* ........ 46* ...... 115*

Mercury 390/325 HP .................. .481"/.490" ......... 270*/290* ........ 46* ...... 115*

American Motors 390/315 HP .... .425"/.425" ......... 266*/266* ........ 44* ...... 112*

Frito,

For these 1968 Power-Plants,

> The Oldsmobile 350/325 HP 'Ram Rod' was the most aggressive.

> The American Motors 390/315 HP was the most mild.

 

[Jarlaxle]

i don't remember any in the group really being much of a performer, but never drove a ram rod.
the 400 gto was o.k.

They moved, but they NEEDED to spin. IIRC, the Ram Rod had 3.91 gears standard, with 4.10's, 4.33's, and 4.56's optional. (IIRC, they weren't available with A/C for the same reason.)

Wow...308 degree cam in a 350...no wonder they were screamers that would barely idle!

 

[69 Cuda 440]

Jarlaxle,

The 1968 Oldsmobile Cutlass 'Ram Rod' {350/325 HP}

4-Speed Only Cars

Those 'stock' cars sounded the best with that Camshaft.

 

[69 Cuda 440]

Are we talking Carburetors,

Road Runner 383..................... Carter AVS {625 CFM}....... Model #4426 or #4401 ------------- 1.563" x 1.686"

Super Bee 383......................... Carter AVS {625 CFM}....... Model #4426 or #4401 ------------- 1.563" x 1.686"

Chevrolet 396/350 HP.............. Rochester {750 CFM}....... Model #7028217 or #7028218 ---- 1.375" x 2.250"

Chevrolet 327/325 HP.............. Rochester {750 CFM}...... Model #7028299 --------------------- 1.375" x 2.250"
{*Specially Calibrated by the Factory}

Buick 400/340 HP..................... Rochester {750 CFM}..... Model #7028240 or #70288242 --- 1.375" x 2.250"

Oldsmobile 400/350 HP............ Rochester {750 CFM}..... Model #7028251 --------------------- 1.375" x 2.250"

Oldsmobile 350/325 HP............ Rochester {750 CFM}..... Model #7028255 --------------------- 1.375" x 2.250"
{*Specially Calibrated by the Factory}

Pontiac 400/350 HP.................. Rochester {750 CFM}.... Model #7028263 or #7028268 ----- 1.375" x 2.250"

Pontiac 350/320 HP.................. Rochester {750 CFM}.... Model #7028269 --------------------- 1.375" x 2.250"
{*Specially Calibrated by the Factory}

Ford 390/325 HP....................... Holley {600 CFM}.......... Model #3793 or #3795 ------------- 1.563" x 1.563"

Mercury 390/325 HP................. Holley {600 CFM}.......... Model #3793 or #3795 ------------- 1.563" x 1.563"

American Motors 390/315 HP ... Carter {600 AFB}.......... Model #4583 or #4584 ------------- 1.437" x 1.686"

 

[Jarlaxle]

Jarlaxle,

The 1968 Oldsmobile Cutlass 'Ram Rod' {350/325 HP}

4-Speed Only Cars

Those 'stock' cars sounded the best with that Camshaft.

Could have sworn there was one at the Pure Stock Musclecar Drag Race a few years ago with an automatic and 4.11's...

 

['73red-duster]

From what I've read about the Ram Rod, '68's only came with 4-speeds. '69 were available with auto's.

 

[69 Cuda 440]

1968 Oldsmobile Cutlass 'Ram Rod'

* 4-Speed Only

* Note: Several 'Ram Rod' cars were equipped with an M-14 {3-Speed Manual}

* Hurst Shifter

* M-20 Transmission {Wide-Ratio}
* M-21 Transmission {Close-Ratio}

* Factory Gears .......... 3.42 or 3.91
* Dealer Optional ....... 4.33 or 4.66

 

[Abodybomber]

Chevrolet 327/325 HP.............. Rochester {750 CFM}...... Model #7028299 --------------------- 1.375" x 2.250"
{*Specially Calibrated by the Factory}
Boy,I would love to see the circuit tweaks back then,on a factory Q-jet install with 78 on overlap & a stock type drivetrain. Dist curve,as well......

 

[69 Cuda 440]

A-Body-Bomber,

General Motors tweaking

I know the Oldsmobile 350 'Ram Rod' Rochester MV #7028255 was tweaked beyond belief.

That Carburetor was already pulling 730 CFM @ 5000 RPM's, and the 350/325 HP engine could rev up to 6000 RPM's.

Special Components
* Primary Main Jet #7031974 {.074" size}
* Needle and Seat Assembly #7023897
* Secondary Metering Rod #7033658
* Throttle Body Assembly #7036514
* 7/8" Fuel Inlet with a Special Fuel Line

Supposedly the Carburetor had the Primary Rod removed, as well as the Power Piston.

 

[69 Cuda 440]

Get Your 'Stock' 1968 Cast Iron Intake Manifolds

Make/Engine............................ Weight ............... Aluminum Replacement
----------------------------------------------------------------------------------------

Mopar 383 ............................... 40 lbs. ................ 19 lbs.

Chevrolet Big Block ................. 48 lbs. ................. 22 lbs.

Chevrolet Small Block ............. 40 lbs. ................. 16 lbs.

Buick 400 ................................ 48 lbs. ................. 22 lbs.

Oldsmobile 350/400 ............... 58 lbs. ................. 25 lbs.

Pontiac 350/400 ..................... 56 lbs. ................. 22 lbs.

Ford 390 ................................. 78 lbs. ................. 28 lbs.

American Motors 390 ............. 47 lbs. .................. 20 lbs.

 

[69 Cuda 440]

1968 > '383/335 HP'

In 1968 at the Drag Strip, the Road Runner and Super Bee were 'strangled' in E/S or E/SA {10.00 to 10.49 Wt/Hp}.

As we know, Mopar over-rated the Horsepower of the 383, and were stuck between a 'rock-and-a-hard-place'
for Sales and Marketing purposes.

For general 'street performance', both the 1968 Road Runner and Super Bee were solid performers, and durable beyond belief.

But if anything, the 383 Engine needed '3' simple improvements;

* Camshaft {.484" Lift ~ 284* Duration ~ 68* Overlap ~ 108* LSA}
* Aluminum Dual-Plane High-Rise Intake {Edelbrock #DP-4B}
* Carter 750 AVS or Holley {#3310-1} 780 CFM Carburetor

"Now that's what I'm talking about."

 

[SRT_DSTRHOLC]

My dad use to have a 68 383 with suregrip. He said the only thing that would beat him were vettes, but at that time, there was nothing else that could stay with him.

 

[69 Cuda 440]

Lets Talk Exhaust,


Make---------------------------Header Outlet ----Exhaust Pipe-----Tail Pipe

Mopar 383/335 HP ..................... 2.50" .............. 2.25" ............. 2.00"

Chevrolet 396/350 HP ............... 2.50" .............. 2.25" .............. 2.25"

Chevrolet 327/325 HP ............... 2.50" .............. 2.00" .............. 2.00"

Buick 400/340 HP ..................... 2.25" ............... 2.25" .............. 2.00"

Oldsmobile 400/350 HP ............ 2.50" .............. 2.25" ............... 2.00"

Oldsmobile 350/325 HP ............ 2.25" .............. 2.25" ............... 2.00"

Pontiac 400/350 HP .................. 2.00" .............. 2.25" ............... 2.25"

Pontiac 350/320 HP................... 2.00" ............... 2.25" .............. 2.25"

Ford 390/325 HP ....................... 2.03" ............. 2.00" ............... 2.00" {System equipped with an 'H-Pipe'}

American Motors 390/315 HP .... 2.00" ............. 2.00" ................2.00"