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Old 10-03-2011, 05:01 PM   #21
Paul Ceasrine
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Default Re: 1968 Pontiac GTO

GTO Hood Tachs;

The 1969 GTO Ram Air IV Tach (only)
5500 RPM Red Line



The early production Tach for the 1968 GTO's
(400/350HP and 400/360HP 'HO' engines)
5200 RPM Red Line
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Old 10-03-2011, 05:02 PM   #22
Dan Fahey
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Default Re: 1968 Pontiac GTO

I had a 68 GTO in E/SA. Could not get it to run right.
Just lacked time going to college 1974.

For the longest time none of the 68/69 GTO engines was a good class fit.
The Cams had very low lift and nominal increase with the 366hp.
NHRA and IHRA at the time were strict on HP and Weight and having the correct Emblems.

There were some advantages, combustion chamber was machined.
had the same rocker set up as the SBC and BBC.
Easy to maintain than a SBC or BBC as you could get to the Plugs easier.
The Engine seems to like the 4.33's the best with a 28 inch tire.

There was one driver who made the Firebirds rock in B, C and D Stock for a long time.
Forget his name..but ran the RA IV combination

One cool rumor was that Pontiac and Buick divisions at the time were vying for some kind of dominance.

There was a quietly publicized race that happened between a RA V and GSX.
Nobody seems to know who won that race.


Dan
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Old 10-03-2011, 05:32 PM   #23
Paul Ceasrine
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Default Re: 1968 Pontiac GTO

Fred Borcherdt
'Rocky's Goat'
1969 GTO 'The Judge',,, w/Ram Air IV (400/370HP)
sponsored by Rock Hill Pontiac, Newark, Delaware

1969 Photo (Classed in D/SA) (9.00 - 9.49 wt/hp)


In 1970, held the E/SA National Record (both ends)
12.10 @ 114.79 MPH,,,,,, (Set in May 1970)

1970 E/SA Class; (9.00 - 9.49 wt/hp)

Last edited by Paul Ceasrine; 10-05-2011 at 03:24 PM.
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Old 10-04-2011, 11:33 AM   #24
Paul Ceasrine
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Default Re: 1968 Pontiac GTO

Tiny E,

I stumbled upon another GTO site with some other performance tests done back in 1968.

Hot Rod Magazine tested a mid-year 1968 400/360HP 'Ram Air I'.
4-speed, with 3.90 gears on G77 x 14" tires.

In stock trim,,,,
14.25 @ 99 MPH

With 7" Casler Slicks
13.85 @ 102.13 MPH

Also, John DeLorean pounding the 'Endura' bumper with a sledgehammer!



1968 Pontiac GTO, in 'I Dream of Jeannie'

Last edited by Paul Ceasrine; 10-04-2011 at 04:10 PM.
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Old 10-05-2011, 12:18 PM   #25
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Default Re: 1968 Pontiac GTO

Ray,

For 1968, Pontiac GTO w/400 engine, car weight #3504 lbs.

400/350 HP (Standard engine car),,,,,,,,,,classed in E/S (10.01 wt/hp)
400/360 HP ('HO" High Output Engine),,,classed in D/S (9.73 wt/hp)
400/360 'RA I' (Ram Air I Engine),,,,,,,,,,,,,classed in D/S (9.73 wt/hp)
400/366 'RA II' (Ram Air II Engine),,,,,,,,,,,,classed in D/S (9.57 wt/hp)

I'm no Pontiac expert, but I think this is the 68' 400/360 'HO' specifications.
The 400/360 'HO' was the first performance engine option for the 68' Pontiac.
It was also known as; the 400/360 HP 'Non-Ram Air Engine'

Block Casting #'s: WS or YZ
Pistons; 10.75-1 compression
Cylinder Heads; #16 casting's (2.11" Intake / 1.77" exhaust) (72 to 75 cc's) (Open chamber)
Cast iron exhaust headers
Camshaft; (Hyraulic) .425 intake lift / .424 exhaust lift (288*/301* duration) (119 Centerline) (63* Overlap)
Cast iron intake manifold
Rochester Quadra-Jet (750 cfm) Model #7028267

The Rochester carb on the 400/360HP 'HO' was different than the 400/350HP carb,
with a larger Main Rod, and some other minor up-grades;
Throttle openings: 1 3/8" Primary / 2 1/4" secondary
Main Jet: #72
Main Rod: #41
Spring: #7037305
Secondary Rod: #BE

The #16 Cylinder heads, had regular valves, screw-in studs, dual valve springs and 'D' port exhaust.
Considered a good general all-around performance cylinder head.

A true performance test by Motor Trend Magazine (December, 1967)
400/360HP 'HO", TH-400 Automatic Transmission, w/3.23 Posi Gears
G77 x 14" tires
15.10 @ 90 MPH

Suprisingly, 400/360HP 'HO' production numbers are quite high, only a ($76) option.
9303,,,,,,,, Manual 4-Speeds
4007,,,,,,,,,TH-400 Automatics
13,310,,,,,,Total


pc

Last edited by Paul Ceasrine; 10-06-2011 at 03:01 PM.
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Old 10-05-2011, 02:06 PM   #26
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Default Re: 1968 Pontiac GTO

Quote:
Originally Posted by Paul Ceasrine View Post
Ray,





A true performance test by Motor Trend Magazine (December, 1967)
400/360HP 'HO", TH-400 Automatic Transmission, w/3.23 Posi Gears
G77 x 14" tires
15.10 @ 90 MPH

pc

That seems a touch slow, my father was turning that at Alton with his 65 Tempest. 326/285hp "HO" 4speed and a 3.36 posi. I know my father wasn't the best, but he knew his car and it is still the same one sitting in my shop. Still the same down to the original hoses. It is the car that made me a car guy.
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Old 10-06-2011, 08:57 AM   #27
SCOTT SST2871
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Default Re: 1968 Pontiac GTO

Quote:
Originally Posted by paul ceasrine View Post
danny,

i think the road runner thread will get more hits,,,,,,,,,

though the gto was the '1968 car of the year', there were quite a few mixed reviews for the car.
Hot rod magazine called it, 'the best balanced car pontiac's ever built'

car life magazine stated, 'a nose-heavy, under-steering lump'

performance results;
15.93 @ 88 mph,,,,,,(car life),,,,,,,,,,400/350hp, automatic, w/3.23 gears

15.50 @ 90 mph,,,,,,(car & driver),,,400/360hp, automatic, w/3.55 gears ('ho')

15.10 @ 94 mph,,,,,,(hot rod),,,,,,,,,,,400/360hp, automatic, w/3.90 gears ('ho')

14.70 @ 97 mph,,,,,,(motor trend),,,,,400/360hp, 4-speed, w/4.33 gears ('ram air i')

14.50 @ 98 mph,,,,,,(car craft),,,,,,,,,,,400/360hp, 4-speed, w/3.90 gears ('ho')

14.25 @ 99 mph,,,,,(super cars),,,,,,,,400/366hp,,4-speed, w/4.33 gears ('ram air ii')

note: All performance tests were performed in a stock dealership car, with g70 x 14" tires.

When comparing apples-to-apples, the 68' gto 400/350hp and the
road runner 383/335hp were pretty much equal in the 1/4 mile
with 4-speed transmissions, but when comparing automatic transmissions, the road runner could outrun the gto.

im a pontiac guy but you can tell times have changed i took my daily driver 08 pontiac g5 to the track last week and ran it ,15.89@89mph 4cylinder no turbo bone stock and got 30 mpg going there!
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Old 10-06-2011, 12:14 PM   #28
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Default Re: 1968 Pontiac GTO

Maybe a better view of the 1968 GTO,,,

Car Life Magazine
May 1968

400/360HP 'HO'
4-speed
w/3.90 Posi-Rear
G77 x 14" Tires
14.53 @ 99.7 MPH

A more presentable performance.
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Old 10-17-2011, 10:27 AM   #29
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Default Re: 1968 Pontiac GTO

Ed,

The 1968 Pontiac GTO 'Ram Air I'.

Option Code #342,,,,,,$342.89

The 400/360 HP 'Ram Air I' was more potent than the 400/360 'HO'.

Block Casting #'s; WS or YZ (4-Bolt Main Blocks)
Pistons; 10.75 compression,,,, (same as the 'HO')
Cylinder Heads; Casting #31 (2.11 Intake / 1.77 Exhaust) (72 cc's) (Open chamber)
Cast Iron Exhaust Headers,,, (same as the 'HO')
Camshaft; (Hydraulic) .425 Intake / .424 Exhaust (301*/313* Duration) (119 Centerline) (76* Overlap)
Rochester Quadra-Jet (750 cfm) Model #7028275
Cast Iron Intake Manifold (#9790140 same as the 'HO')

The main engine differences between the 'Ram-Air I' and the 'HO' were,
the 'Ram-Air I' had a 4-Bolt Main Block, and the #744 camshaft, which had more duration
and overlap.

The #31 casting cylinder heads had the same valve and port size, but the combustion chambers were a true 72 cc's. (Generally regarded as better casting cylinder heads).

The cast iron intake manifolds (#9790140) were the same on each engine.

Both engines had the special long-branch cast iron exhaust manifolds.

The Rochester 750 CFM carburetors were almost identical, except the
# 7028275 'Ram-Air I' carburetor had more jet area.
---------------------------------------------------------------------------------------------------------------------------------

All GTO Ram-Air cars were to be equipped with 4.33 gears.
But the mandatory Safe-T-Track Differential option (Code #361) was required ($63.19)

The M-21 close ratio 4-speed was an option (2.20 1st, 1.64 2nd, 1.28 3rd, 1.00 4th),
Code #358 for a cost of ($184.31)

The 'Ram Air I' 400/360HP cars were built between December 1967 thru March 1968.
--------------------------------------------------------------------------------------------------------------------------------

The 400/360HP 'Ram Air I" did make its mark early.
At the 1968 NHRA Winternationals, Gary Brookshire out of Visalia, California
won the D/Stock Class with his new 1968 GTO.
Ran 12.70's @ 110 MPH.
As he took out a host of 68' Mopar GTX 440's, and 68' Olds 4-4-2's.

Last edited by Paul Ceasrine; 10-18-2011 at 01:43 PM.
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Old 10-19-2011, 10:12 AM   #30
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Default Re: 1968 Pontiac GTO

Super Stock & Drag Illustrated Magazine
October 1967



In November 1967, Royal Pontiac (Royal Oaks, Michigan) did a performance test for the editors of Super Stock & Drag Illustrated magazine.

The car was a 'new' 68' GTO 400/360 HP 'Ram Air I', 4-Speed (with P/S and P/B) and
4.33 gears.

The GTO underwent a 'Royal Bobcat Level I' up-grade.
The car had the 'dealer installed' Ram-Air hood scoop package.

The cylinder heads were removed, and replaced with a set of Royal Pontiac
(Casting #31) prepared 'blueprinted' units;
* 3/angle valve job
* milled and cc'd
* valve spring shim height set
* rocker-arm lock nuts
* thin cylinder head gaskets

Note: Compression ratio was estimated at 11.5 - 1 (over the stock 10.75 -1 ratio)

* The distributor mechanics were replaced with a performance re-curve kit.
* Larger jets were installed in the Rochester 750 CFM carburetor.
* Colder Champion J10Y spark plugs were installed.
* A heat-riser block gasket was used for the intake manifold.
* A set of Doug's Headers were installed.
* The exhaust pipes, mufflers and tail-pipe extensions were removed, to lighten the car.
* A set of M & H Slicks (8.00" wide x 14") were installed on Hurst (14" x 6") Rallye wheels.

The performance test was supervised by Milt Schornack, Head of the High-Performance
Division of Royal Pontiac.

Driver; John Kosmala of Royal Pontiac

Results: 12.93 @ 108.05 MPH

This was the supposed car;
White with gold rocker panel moldings, and a gold stripe painted
down the hood center, an Endura front bumper, hidden headlights, and Hurst (14" x 6") Rallye wheels.

Last edited by Paul Ceasrine; 10-26-2011 at 08:46 PM.
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