A Guide to Y Code Frames

                                                                 By: Patrick Smith

   At first glance, you'd think there's nothing to a Y Code frame. What's there to know? Once you start restoring one, a bunch of differences appear. Stuff you didn't realize until you order parts and realize they aren't the same. Or until you buy a replacement frame for your rusted or bent original and discover stuff isn't the same. We're going to walk you through the frame differences and show you.

   Let's tackle the 1971 GTO frames first. Since a lot more of them were made than 1972s it stands to reason you might consider using one as a donor. For 1971, Pontiac issued three separate frames for that year. PN 3992389 was the standard frame for engines up to 400 cid displacement. It was open channel, swept hip perimeter design.The only areas boxed were the engine cradle frame horns and the side rails along the rear suspension and axle kick ups.

  

Frame Part Numbers :
  The 455 engine frame used PN 483709 and featured differences in construction from the basic frame. This one used rear frame reinforcement straps leading from the rear axle to the rear suspension bulkhead. The 455 also used a 12 bolt Chevrolet axle assembly instead of a 10 bolt. The engine cradle had special 455 frame to motor mounts installed. Otherwise, it was the same as the standard 400 frame save for the part number and build sheet code. The third frame was PN 483710 and was used for convertible applications and as an optional, HD boxed frame application. It has enclosed side rails instead of open channel and in the case of 455 engine usage it would also have rear frame reinforcement straps and the 12 bolt axle assembly. Reproductions of these parts are readily available by the way.

  For 1972, Pontiac used 3 frames again but with different part numbers. The standard frame PN6263668 was used for engines up to and including the 400 CID. It was open channel swept hip perimeter construction. The 455 engine order paired the body to PN 487227 which was open channel as well but supplied 455 motor mounts, 12 bolt axle with rear frame reinforcements. This was what you got with a Y Code hardtop or coupe order. Since the GTO option wasn't available on a convertible this year, the LeMans Sport was the model you needed to order to get PN 487228 which was a HD boxed frame. It was also used when you ordered the HD boxed frame option for your car. It is theoretically possible to find this frame in a Y Code hardtop or coupe. It will be the frame used in a LeMans Sport convertible.

Engine to Frame Brackets: The 455 engine used different engine to frame brackets from the 400 engine. While you can install 400 engine to frame brackets in your car and they will work, the reason the factory used a different set was to handle the notable increase in low end torque the 455 produced. While it seems overkill for a 1972 era 250 hp engine, the parts were made in 1970 when it was still a high compression engine kicking out 500 lbs ft with over 10:1 compression ratio. It's cheap insurance!

  

These are the 400 cid engine to frame mounts. Note triangular shape and  bulge leading to
the inner mounting hole.  This is your key ID method and the different location compared to the 455 mounting in engine cradle.  

  Anyway, here is a pic of the standard 400 cid engine to frame mount set. Niote they are triangular in shape with a pass through for the rubber motor mounts.  Various vendors sell these and they're cheap to get. If you plan to put your car back to original specs, use the 455 specific engine to frame mounts. Here is what they look like.

  

For lack of a better word, the 455 mounts are more squared off and lower than the 400 mounts.
These are also more expensive too. This set appears to be black coated while mine are dimpled metal in silver and thick.

 As you can see, the 455 engine to frame mounts are slightly different. Notice how the metal is  shorter and lower. There isn't a steep rise going up to the pass through. It's compact. The location is different on the engine cradle as well. Next have a look at where the 400 engine mounts go in the cradle and compare it to a 455 engine to frame mount. Unmistakable difference once you see it.

  

455 engine frame mounts, note different shape and overhang on front of frame.

   

  Above is a pic of a 455 chassis with the 455 engine frame mounts in place. Note how it overhangs the front of the cradle slightly?  The 400 mounts aren't placed there.

  

Here is another angle of a 455 engine to frame mount. See how far out they
reach past the cradle. Ron Bavis pic credit:    

    Now that one is cropped a bit so you can't really see much in terms of placement in relation to the engine cradle. I have another photo taken farther away and on an angle so you get a better idea just how high up and far they stick out.

  

455 rubber engine to frame brackets are unique as well and must be used if installing
the engine using 455 engine to frame brackets. 

 455 Engine Mounts: In addition to special frame mounts, the 455 engine required different rubber engine to mount brackets. They were shaped differently from the 400 parts and you cannot mix 400 rubber mounts with 455 brackets. You CAN install a 455 using 400 engine frame mounts but you got to use the 400 rubber pieces as well. Above is a pic of the 455 specific rubber engine to frame brackets.

More often than not you will find these braces on a 455 powered LeMans or GTO.
The ins and out of their presence hinged on whether the car was ordered with rpo Y99 or if it was
a WW4 or WW5 ordered car.

Frame Bulkhead Reinforcements: These goodies are part of the F41 heavy duty suspension option for Olds 442 and Chevelle SS cars. You will find these goodies on 455 powered Pontiac LeMans and GTOs. Pontiac's term for their handling package was rpo 724 or Y99. It wasn't standard on a GTO, you had to order it separately OR order a WW4 or WW5 package. WW4 was the 400 4 barrel engine, 4 speed manual transmission, Saf T Track axle, power disc brakes, custom carpets and handling package. On a WW5 you had to order the GTO option first and then WW5 triggered a massive upgrade including 455 HO roundport engine, Turbohydramatic or  M22 four speed, Saf T Track axle, body color sport mirrors, formula steering wheel, roof drip moldings, power disc brakes, custom carpets, rally gauge cluster and handling package. So the bulkhead reinforcements weren't 455 exclusive but indicated the car was ordered with Y99 suspension which is a pretty good thing!

    2023 Patrick Smith images phs media archives.

PHS Collector Cars 1972 LeMans/GTO Y Code Registry

1972 Luxury LeMans 2 door hardtop

                                                       By: Patrick Smith

    The 1972 PHS Y Code Registry has located another car to add to the survivors database. This one resides in Woodbridge, Ontario, not far from where it was sold brand new. It belongs to Robert Barberio and family. This one is rather special as it has been with the same family since new! Luxury LeMans was a new trim level added in 1972 to capitalize on rising sales of intermediate cars with heavy option content; a trend that started in the mid 196os and grew. Perceiving a demand for these kinds of cars, GM decided to do upscale versions of their best selling intermediates which was how we got to see Chevelle Laguna S3s, Oldsmobile Cutlass Supremes in the formal hardtop body style and a Pontiac Luxury LeMans.

  

Check it out, Sundance Orange with black top and its 455 powered!

   The Luxury LeMans trim level delivered a well appointed car with custom interior, door panels with carpeted runners, pull straps and reflector lenses for safety. Upgraded custom cloth and vinyl upholstery, added woodgrain trim on the lower dash board for the wiper switch, cigar lighter and defroster switch area. The dash pad got an LLM script on the passenger side instead of a plain 'Pontiac' escutcheon. The exterior received a special three bar grille, extra wide belt moldings, LLM script for the  trunk lid, sail panels and front fenders, a chrome plated front valance for the parking lamps, extra wide trunk lid molding and fancy full hubcaps with the red lucite Pontiac center caps. A set of rear fender skirts was also provided. There was extra insulation throughout as well. Oh one other detail, LLMS got the ribbed tail lamps carried over from 1971 as a dress up feature. A few GTOs and LeMans got them as well since it was a build out year and parts bins were cleaned out instead of ordering new inventory.

 

Luxury LeMans  cars got this brushed steel appearance trim for trunk lid.

 LLMS were sold as two door and four door hardtops only. There were no convertibles or coupes made. The biggest engine offered was a 250 hp 4 barrel L75 powerplant of 455 cubic inches; Y for the VIN number code. It was a d port 455 designed for brute torque instead of top end power. The only transmission offered was the TH400 automatic in column or floor console shift. You also got a Chevrolet produced 12 bolt carrier and the extra support straps above the control arms.

   

Vintage Vehicle Services form showing options.Great Canadian version of authenticating
your car.

   Robert's dad bought this one new from Weston Chev- Olds in December, 1971. Some kind of Christmas present! Check out the options on this baby. AO1 tinted glass, all windows, A51 bucket seats, B84 body side moldings, C41 heater defroster, C50 blower style rear defogger, D35 body color sport mirrors with remote, D55 front console, GX2 rear axle ratio 3.31, JL2 front disc brakes, LO8 engine emissions certification, L75 455 4 barrel 25o hp, M40 TH400 transmission, N10 dual exhaust, N41 power steering, N98 rally II wheels, PK2 G78 x 14 tires HWY BB w walls, PO6 wheel trim rings, U35 electric clock, U57 tape player, U65 am radio, U71 windscreen antenna, W63 rally dash +clock, W84 extra fuel delivery, Z49 Mandatory base Canadian Equipment.

  

  The cowl tag shows it was factory Sundance Orange with black bucket seats and it was built in early December 6th 1971at the Oshawa plant. The engine serial number is C2253824. The most remarkable thing is the car was kept all these years in the same family with  Robert taking over the reins last year. How many cars you know of that stay with the original owner....for 49 years? This is awesome to see!

                     *Article 2023 patrick smith. pics (C) robert roberio

              (C) phs GTO LeMans Y code registry

A Y Code Curiousity-- Dealership created 1972 GTO convertible

                                By: Mike Noun & Pat Smith

    

The special order LeMans Sport convertible shortly after pick up. Notice the door edge guards aren't installed yet. The raised white letter tires are Uniroyal spec which was what Pontiac used along with General Tire for 70 x14 tires with rwl. Goodyear Polyglas was offered in G60 X15 size as tires extra large but was restricted to GTO model. pic credit Mike Noun archives.

    Every so often one hears about an alleged 1972 GTO convertible. The long and short of it is, Pontiac never produced one. The GTO convertible model was dropped for good in winter of 1971 along with the high profile thief and cop bait GTO Judge model. Both were poor sellers and when new general Pontiac manager MacDonald came into power he decided it was time to tone down Pontiac's overt emphasis on high performance. Of course, not everyone agreed with MacDonalds's premise. A certain dealer in Peru, Indiana was having none of it.

 

As you can see, interior was well equipped. This late in the year the custom door panels had pull straps and no 1971 GTO emblems. That set up was early 1972 orders only. To see this setup check the white GTO hardtop in this registry.  pic credit: Mike Noun archives.

   As a sponsor for the Indianapolis Sprint Cars race series at Indianapolis Speedway, Beloff Pontiac ordered a 1972 LeMans Sport convertible to be shipped to their dealership for pace car duties. It was ordered nicely loaded with a bunch of cool stuff. Check out the order invoice Mike Noun supplied us; Top of the list was the L75 455 4 barrel V8 with TH400 automatic transmission. This was a D port engine and therefore a Y Code car in the serial number. It gets better with Safe T Track differential packed in a 12 bolt carrier. (All 455 ordered LeMans got 12 bolt axles as mandatory optional equipment. You had to pay extra for limited slip though.)

  

   The tires were G70 x 14 inch white letter fiberglass backed on optional 14 inch honeycomb wheels with trim rings. Inside we got AM FM stereo, rear speaker hidden under the folding roof in a well. front console, body color sports mirrors with driver side remote, visor vanity mirror, custom seat belts (also known as exploding buckle belts for their tendency for the spring to crack the black plastic retainer cover and propel the button, spring, cover all over the place) custom sport steering wheel, tilt steering, power steering, power disc brakes, soft ray tinted glass,  air conditioning, t 41 Endura front end, D98 white vinyl stripes (buyer had a choice here as a LeMans Sport, he could opt for sword stripes or  the lazer stripe in either black or white depending on body color. As the car is Cardinal Red, the lazer stripes were white and GTOS were offered with lazer stripes.)

  

    The car also got heavy duty battery which meant side posts, rally gauges cluster with tachometer, and last but not least, a decor group which supplied custom sport steering wheel, pedal dress up, wheel well moldings, deluxe wheel covers, rear hood molding and rear bumper guards. The honeycombs superceded the wheel covers and custom sport steering wheel superceded the wood grain cushions wheel. The total for all this was $5,254.60. According to Mike Noun's original article on this car back in the April 2018 edition of Smoke Signals magazine, the order was placed twice. 

   The first time head office kicked it back since the salesman checked off GTO option which was unavailable on a convertible. It was re ordered again with RUSH placed on it and the GTO option still checked. The staff had to talk with Zone Office and stress the sponsorship angle to get it built. The Pontiac plant handled the build and Beloff Pontiac sent their own truck to the plant to pick it up. 

  

Proof this car was not a 455 HO as evidenced by no ram air pans, cleaner etc and a dual snorkel air cleaner.  Definitely a Y Code however. Notice the dealer even added a chrome 1970 air cleaner lid?

  A couple of things were added at the dealer prior to use as a pace car. A set of checkered flag stanchions were added to the rear bumper and trunk. A King Transmission shop decal was added, likely after a shift kit installation and a 455 HO decal was added to the trunk as well as GTO grille emblem. An interesting detail to note is the fender panels with die cast  455 call outs.

  

Just visible above the bumper lip where the wheel well molding meets is a die cast 455 call out. Pontiac used these on LeMans Sports cars when T 41 endura nose was ordered. A GTO would have received quarter panel 455 CID call outs for a Y Code and 455 HO call outs for an X Code. Strangely, the dealer only put the trunk lid decal on. Also note, no ram air hood decal indicating D port dual snorkel set up was delivered from factory. pic credit: Mike Noun archives.

   This makes sense for a LeMans Sport which used die cast call outs for the 350 and 400 engine on the rocker panels, but when its a 455 powered car, the die cast emblems switched to front fender units, mounted behind the side marker lenses and were a completely different part number and shape. 

  This car was last seen at a restoration shop at the time the article was produced and is most likely done now. Mike Noun wrote the original story for Smoke Signals back in  April 2018.Mike has kindly loaned me use of photos from his archive which is greatly appreciated. I hope Alex reaches out to us in future to help record details on Y Code Le Mans and GTOs.

   *Article 2023 patrick smith with use of materials from Mike Noun. All pictures from Mike Noun & Alex Beloff.

Addition: 1972 Y Code Hardtop GTO in Quezal Gold

                                                                    By: Patrick Smith

  This particular car has been around awhile but attempts to contact the dealer at the time went nowhere. After it sold, some data finally shook loose and I was able to confirm it was indeed a true d port 455 car. This one is nicely optioned from the factory and is a really attractive example of what Pontiac Motor Division had in mind for the base 455 engine. 

   

Note 455 die cast call outs on rocker panels. We are still researching this detail. Talks with Dan Jensen
confirmed that only LeMans Sport models had front fender piercing for 455 call outs which were unique emblems not at all like the rocker panel pieces which are slanted thin at top and thick at bottom. We know of 3 cars that have rocker panel 455 call outs.

  Unlike Oldsmobile and Chevrolet, the jump to 455 cubic inches was done primarily to allow adding power accessories to the list without loss of required "passing power" torque. The 1970 455 wasn't really engineered as an all out performance block. It retained d port cylinder heads and there was no ram air induction package until mid year and it was an extra cost option. By 1971 the round port 455 HO appeared and it became the high performance block while the d port was paired to a TH400 as sole transmission.

  

Note incorrect decals here in red with 455 HO notation, this car is actually a d port 455, not an X code round port 455 HO. A few d port cars have been cloned into X codes over the years. Duck tail spoiler is an aftermarket piece and not factory.

  It still has formidable torque and a low enough compression ratio to make driving on pump gas possible. You can even bump up the static ratio a thanks to the combustion chamber size. When new, this car came out with a dizzy load of options; starting with GTO option, th400 transmission, tape stereo 8 track, body color sport mirrors, custom seat belts, honeycomb wheels, door edge guards, power disc brakes, trim package pdl, frt floor mats, rear defogger, power locks, air conditioning, firm ride springs and shocks, custom trim, luggage lamp, underhood lamp, glovebox lamp, heavy duty battery makes up column 1. Whew, column 2 continues with L75 455 4 barrel engine, safe t track differential, stereo radio, console, visor vanity mirror, formula strg wheel, wheel well moldings, power steering, tilt steering, rear floor mats, soft ray tinted glass, power windows, power seat L, California emissions package, rear hood molding, dome interior lamp, courtesy instrument panel lamp, ashtray lamp, dual horns and rally gauges.

  

The sales invoice for this particular car shows it was loaded new. Note no spoiler option listed and L75 engine was specified engine. It would have the dual snorkel air cleaner and no ram air underhood equipment at all.

   The total for this was $4,463.00 and some change. It was shipped to John Hine Pontiac in San Diego California by  Dec 16th 1971 so it's an early build car with chrome rear view mirror and 140 mph speedometer. It was built at the Fremont plant in California as well so it had the California spec carburetor and distributor, two low production Y Code items. Note that this car as restored got rocker panel trim which was GTO spec but also 455 metal call outs which as far as we can tell, wasn't available. My car has them and so does one other hardtop. The owner of the hardtop swears it came that way new. Normally a Y Code GTO would get quarter panel callouts of "455 CID" only. This is something we are still researching so I can't say with 100 percent certainty this wasn't factory. We will return soon with another cool entry of interest.

*Article 2023 patrick smith, images from phs media archives.