Match Race 1972 ~ 'Road Runner/GTX 440' vs. 'Buick GS 455'

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In a Match-Up of 4-Speeds.

I'll take O-M-R {Rick} behind the wheel in the Road Runner w/GTX 'option'.

And the 'Indestructible'........{Code E86} GTX Drivetrain

'Standard Equipment' ..... 'HEMI' 4-Speed '18-Spline' and Dana Rear with 3.54 Gears.

A-833 Transmission = 2.44 / 1.77 / 1.34 / 1.00




RRGTX5.jpg
 
...and EVERY buick is heavy!

(...and "squishy")
 
The 'right' exterior color made these 1972 cars.

As well as selecting the Optional {Code V8} 'C' Pillar/Roof Strobe Stripe.


DSC06730r-1.jpg


1972_Plymouth_5r-2.jpg
 
Performance Results

1972 Plymouth Road Runner w/GTX Option

440/280 HP {U-Code}

* Automatic w/3.23 Gears .......................... 14.80 @ 91.8 MPH
* Automatic w/3.55 Gears .......................... 14.62 @ 94.8 MPH

* 4-Speed with Dana Rear w/3.54 Gears..... 14.48 @ 96.6 MPH


440/290 HP {U-Code} with {Code N96} 'Air Grabber' Fresh Air Package

* Automatic w/3.23 Gears .......................... 14.67 @ 95.1 MPH
* Automatic w/3.55 Gears .......................... 14.48 @ 96.2 MPH

* 4-Speed with Dana Rear w/3.54 Gears .... 14.33 @ 97.2 MPH
 
One issue the "GM" A body needs addressed vs the B body, is the rear suspension. As bite increases, IE stickier tires, the coil sprung 4link will show it weaknesses fairly early, with twist/hop. A lot of people just went to the bolt on ladders, and while they did a reasonable job, I used "no-hop" bars on several cars with decent results. A right side air bag for a little preload on big torque/hp cars can make a big difference also.
 
451Cuda said:
I thought '72 was a thermoquad?
Click to expand...

No,

In 1972, the 440 'U-Code' High Performance Engine came through with a Holley H-4-4160 Series.

Primary......... 1.563" {1 9/16"} ~ Venturi 1.250"
Secondary .... 1.750" {1 3/4"} ~ Venturi 1.563"

The Holley #H-4-4160 was Rated at 670 CFM's.

643676705_tp.jpg



The 440/290 HP with the 'Fresh Air Package' utilized a;
* #6254 {Manual}
* #6255 {Automatic}

The 440/280 HP High Performance Engine utilized a;
* #6252 {Manual}
* #6253 {Automatic}
 
69 Cuda 440 said:
No,

In 1972, the 440 'U-Code' High Performance Engine came through with a Holley H-4-4160 Series.

Primary......... 1.563" {1 9/16"} ~ Venturi 1.250"
Secondary .... 1.750" {1 3/4"} ~ Venturi 1.563"

The Holley #H-4-4160 was Rated at 670 CFM's.

643676705_tp.jpg



The 440/290 HP with the 'Fresh Air Package' utilized a;
* #6254 {Manual}
* #6255 {Automatic}

The 440/280 HP High Performance Engine utilized a;
* #6252 {Manual}
* #6253 {Automatic}
Click to expand...

Was not aware that they were still using a Holley for that application.
Learning something new everyday.
 
If I remember right the GS stage 3 was quick but the Stage one wasn't all that. I gotta stick with my life's blood on this one. GTX
 
Before I post the Buick GS Stage 1 'specs'.

In 1972, Plymouth discontinued the GTX Model.

You had to purchase a Road Runner, with the 'GTX option' to get the 440 'U-Code'
Engine.

The Code E86 '440 Package' was only $161.

For only an additional $67, you could add the Code N96 'Fresh Air Package' that came
with the 'Air Grabber' Pop-Up scoop.

This came with the complete under-hood Cold-Air Induction System.
* Special Hood
* Plastic under-hood air box
* Special lower Air-Cleaner base
* 'Coyote Duster' Air Cleaner lid
* Hood Scoop system with vacuum actuated control
* Hood Decal

And, the 'specially-calibrated' Holley H-4-4160 Series 670 CFM Carburetor.

Though not advertised, the 'Fresh Air Package' was worth an additional 10 Horsepower
 
OldmanRick said:
One issue the "GM" A body needs addressed vs the B body, is the rear suspension. As bite increases, IE stickier tires, the coil sprung 4link will show it weaknesses fairly early, with twist/hop. A lot of people just went to the bolt on ladders, and while they did a reasonable job, I used "no-hop" bars on several cars with decent results. A right side air bag for a little preload on big torque/hp cars can make a big difference also.
Click to expand...

I painted with kind of a broad brush with my above post, so to explain more of what I experienced........

The "sway bar" cars along with the boxed lower control arms vs the flimsier open stamped units were actually pretty good, as long as the stock ride height was maintained. I found that along with a good 50/50 shock, it was a decent system for street cars...especially automatics.

The real issues came with increased ride height, which many people did back then via bigger coils or air shocks.

The geometry of the short/angled upper control arms was easily thrown out of wack as the height increased. That's where the "No-Hop" bars really did their thing by raising the rear mounting point back to a more favorable position.
 
My first post in a loooong time, and here I am backing the wrong company! I grew up around Buicks, even the 72' Skylark Custom with the 350 4bbl that was my parents daily until 94' was suprisingly quick. Honestly, I think it boils down to tuning and the driver. I'm going with the Buick, especially with the 3.42 rear. With all the torque, thats all it needs! Believe it or not, Buick engines aren't really heavy (until you put that mile wide cast iron intake into the equation lol). I honestly don't think I would place a bet on this one though.
 
1972 Mopar 440 'trick'.

To squeeze another 3/10's off the Elapsed Time.

Mopar made a lighter spring kit for the Distributor Advance {P/N 2084301},
as well as a different Cam and Stop-Plate for the Distributor internals.

Set the initial advance to 15* {at Idle}, and 35* Total {at Full Advance}

And on the Holley Carburetor, enlarge both the Primary and Secondary Jets,
one size.

It made a 'World of Difference'.
 
Slick trick on GM single point dizzy's from back in the day.....

Place about a 3/8" length of windshield washer hose behind the point arm on any stock replacement set.......Prevented point bounce and no high dollar, Accel or Mallory's needed. :thumbrig:
 
OldmanRick said:
I painted with kind of a broad brush with my above post, so to explain more of what I experienced........

The "sway bar" cars along with the boxed lower control arms vs the flimsier open stamped units were actually pretty good, as long as the stock ride height was maintained. I found that along with a good 50/50 shock, it was a decent system for street cars...especially automatics.

The real issues came with increased ride height, which many people did back then via bigger coils or air shocks.

The geometry of the short/angled upper control arms was easily thrown out of wack as the height increased. That's where the "No-Hop" bars really did their thing by raising the rear mounting point back to a more favorable position.
Click to expand...

Excellent information, and exactly what I did to my El Camino's in Y2K era. Have to get the I.C. moved forward. Used the Global West Del a Lum bushings as well. In the actual race,Mopar by 2-3 car lengths. As Ricky stated,all down to driving/tuning.
 
OldmanRick said:
Slick trick on GM single point dizzy's from back in the day.....

Place about a 3/8" length of windshield washer hose behind the point arm on any stock replacement set.......Prevented point bounce and no high dollar, Accel or Mallory's needed. :thumbrig:
Click to expand...


O-M-R

And I bought about 'two-dozen' Accel Distributors for GM's
back in the 1970's.

Threw the GM Factory units in the 'scrap metal bin'........

:violent1:
 
69 Cuda 440 said:
O-M-R

And I bought about 'two-dozen' Accel Distributors for GM's
back in the 1970's.

Threw the GM Factory units in the 'scrap metal bin'........

:violent1:
Click to expand...

Don't feel bad, I owned my share of them also, lol.

I actually learned that from a guy around 74'/75' that ran a single point in a 10sec BB Vette with 5.13's and shifted in the 7300 range.

I still liked the Accel and Mallory Dual point dizzy's better. But for a milder build or in a pinch, it was a pretty good idea.
 
1972 Buick GS 455 'Stage 1'

455/270 HP

280 HP @ 4400 RPM's {Rated at BHP. SAE Net}
390 Ft/Lbs. Torque @ 3000 RPM's

Compression............... 10.5 -1

Pistons........................ Dish Type
Deck Height................ -.010" {Below Deck}

Cylinder Head.............. #1238148
Intake Valve................. 2.130"
Exhaust Valve............... 1.755"
Combustion Chamber... 59.0 CC

Carburetor.................... Rochester #7042242 {Factory Modified}
Throttle Sizes................ 1.375" Primary ~ 2.250" Secondary
Venturi.......................... 1.218" Primary ~ Automatic Vacuum

Distributor................... AC Delco {Factory Advanced}

Camshaft..................... .490" / .490" Lift
 
Have you seen any flow numbers for the Stage 1 heads? I know most Buick castings were the same as far as port dimensions, but with the larger valves???

I did find this posted on V8buick.com from 2006, but it was the "148" casting with standard 455 valves...2.00/1.625.

----------------------------

"Flow results: '72 455 "148" castings, standard valve size (GS 455 heads)

Valve lift in inches
Intake stock Exhaust stock
.100 59 52
.200 120 100
.300 175 124
.400 208 140
.500 218 147
Averages (.200-.500) 180 206 128 149

Specifications: Intake valve size - 2.00" : Exhaust valve size - 1.625

Flow numbers in Cubic Feet per Minute (CFM) flowed at 28" H20"
 
O-M-R

1972 Buick GS 455

Engine..................Intake / Exhaust...........Camshaft.............................................

* 455/225 HP....... 2.005" / 1.630" .......... .397" /.466" .... 258*/268* {Automatic only}

* 455/250 HP...... 2.005" / 1.630" .......... .397"/.466" ..... 260*/276* {4-Speed only}

* 455/270 HP...... 2.130" / 1.755" .......... .490"/.490"...... 316*/340*......'Stage I'


Stage I Cylinder Head

455_head_stage1.jpg
 
OldmanRick said:
One issue the "GM" A body needs addressed vs the B body, is the rear suspension. As bite increases, IE stickier tires, the coil sprung 4link will show it weaknesses fairly early, with twist/hop. A lot of people just went to the bolt on ladders, and while they did a reasonable job, I used "no-hop" bars on several cars with decent results. A right side air bag for a little preload on big torque/hp cars can make a big difference also.
Click to expand...
Yep i've boxed many lowers and added adjustable uppers with a bar and it worked very well on the many A-F body GM'S ran the bar similar to this pic but bolted directly through the sides with 2 bolts on each side. Ed.
 

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