Re: Factory Correct Restoration Details
 

Something I have noticed is that a lot of the factory photos of engines depict fans with clutch assembles. I understand that they would of come on the high performance models but I have also seem them shown on the basic 327 and 350 pictures. I have never seem a factory engine with a fan clutch in this gen truck.

Re: Factory Correct Restoration Details
 

. . . .

Below, are three different pictures of 68 engine's I've saved - WITH the orange bracket !!!

The first with 25,000 original miles.

The second with 57,000 original miles.

The third with 89,000 original miles.

I have a few with a black bracket saved too.

. . . .

Re: Factory Correct Restoration Details
 

I don't think the 2nd pic helps your case, from the pic the engine looks like it was just repainted.
Fresh orange engine paint, new valve cover decal, even the fuel line and tower hose clamp is painted orange.
The air cleaner still in its original old black paint and you can see where the decal used to be.
That pic looks very much like they just repainted the alt bracket the wrong color.

Re: Factory Correct Restoration Details
 

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Re: Factory Correct Restoration Details
 

Sorry to be joining late; I'd like to make a few comments but should make an introduction before I do.

I am a second generation GM employee. My dad worked for GM for 32 years, in manufacturing (pressed metal) and advanced manufacturing engineering. He holds several patents including the invention of laminated steel and is the GM patentholder for the hydroform process. He also raced professionally for Pontiac Motor Division through Royal Pontiac in the mid 1960's.

I have been with GM for 36 years, in vehicle assembly and product engineering. I started at Chevrolet Flint Assembly as a GMI student, my first real job being an assembly line supervisor. I moved into engineering and have been there ever since, as a design release engineer and program level engineer, and have either been resident or launched product in about a dozen different GM plants (Flint, Pontiac, Ft Wayne, Oshawa, Janesville, St Louis, Arlington, Silao, Wentzville, Detroit-Hamtramck and Mishawaka). Because of the Pontiac influence I am also a student of historic assembly process and am quite familiar with the flow and techniques used in the mid 1960's Pontiac Michigan assembly plant.

I currently have design/release responsibility for the underbody structure on the K2XX pickups (as well as the whole pickup box) and the GMT610 vans.

Having said all that: you guys are generally on the right track. I'd like to go back and touch up some of the comments and then make myself available for any specific questions you might have.

K

Re: Factory Correct Restoration Details
 

Agree. Publicity photos or pics of display engines might get you close but not 100% correct. Transmissions were in fact a natural color (silver) and the amount of paint covereage on engines and other components varied by engine plant and operator.

Here is a b&w photo of big blocks in the rack. You can infer the amount of production representative paint coverage from these, but it also gives an idea of the volume of engines used to maintain production.

Incidentally - in one of my previous jobs my responsibility was to review all the brochures, literature and print advertisements for accuracy (so I KNOW some mistakes get out! - lol).

K

Re: Factory Correct Restoration Details
 

Not necessarily - because the various components could/would come from different individual suppliers. Wheel house aprons would be from a different source than the radiator support, or control arms from a different supplier than frames.

There could be slightly different tints and gloss levels on these parts because the parts were painted in diversely different locations, temperatures and mixes.

K

Re: Factory Correct Restoration Details
 

These are from LIFE magazine's coverage of the Tarrytown plant (passenger cars). Good reference in general but maybe not totally accurate for a '67-72 Chevy pickup.

K

Re: Factory Correct Restoration Details
 

Agree - hood hinges are normally either a phosphate or a cadmium coating, giving them a more natural appearance which quickly becomes a "rust" appearance.

K

Re: Factory Correct Restoration Details
 

Writing on the firewall is to give the downstream workers a "heads up" on what is coming.

Vehicles can be marked with option content in the body shop, to aid the guys welding up the cab (and box) to make sure the proper base components are used or appropriate holes added. Vehicles can also be marked with the exterior color to give the painter a heads up of what color to spray or what two tone might be required. Markings can also be added after paint to aid in the trim process, which is why you will often discover numbers and letter both under and over the firewall paint. Lastly - and probably most importantly - vehicles can be marked with the build sequence number, in an attempt to make sure the correct content is added to that truck and to make sure everything stays in sequence.

Although often called "chalk marks" the actual marker was more of a tire marker, or grease pencil, rather than "chalk".

The writing can vary between model years, between plants, even between operators within the same plant. Colors vary, too, since they were not controlled. Normally you will see white or yellow, for contrast, but the truth is sometimes the guy will use a "stogey" that he found on the floor ("red" being another popular color).

Re: Factory Correct Restoration Details
 

This is correct. That is called the "broadcast code".

There is a unique 8 digit part number for each engine assembly. Engines are proliferated based on cubic inch displacement, carburetion, auto vs manual trans, emissions equipment, ignition type, etc. Anything that drives a unique base engine would create a unique part number.

The problem is...that it is difficult to remember an 8 digit part number from the time you look at the build manifest until you pick the correct engine from the rack. This is especially difficult when the engine part numbers happen to be similar, ie:

12345678
12345679
12345680
12445678

etc

In this case thinking "ok...I need to grab a '78..." could be a disaster.

So - the three digit code was created so it would be easier to remember.

The operator knows he needs to grab a "TAA", or a "TAB", or "TDK".

Much easier and eliminates many potential problems of grabbing and placing the wrong base engine.

All engines; anything with a high degree of proliferation (engines, trans, front/rear axles, radiators, battery cables, shock absorbers) would have a unique part number and corresponding broadcast code.

K

Re: Factory Correct Restoration Details
 

Corvette guys have it easy. One plant, one product, relatively low line speed.

Trucks inherently have a greater variety of product (ie, seven engines, four transmissions, two or more wheelbases, two or three cab types, two or four wheel drive, dually vs single rear wheel, etc). The amount of proliferation in the truck world is one of the hardest obstacles to overcome.

Additionally, during the squarebody era, trucks were built across seven different assembly plants. The opportunity for build variation, due to environment or history (past build monuments) was overwhelming. There was even process variation within the same plant building the same product (ie, at Flint Assembly: Line 1 pickup front end sheet metal was built "piecemeal" - one fender added at a time. Line 2 Blazer/Suburban front end sheet metal was installed as a unit - fenders and radiator support added at the same time).

Lastly - there can be variation between shifts and individual operators.

The Corvette guys would have a cow if they knew some the stuff we did/varied in order to get trucks built - 60 jobs/hour (that's one truck every minute).

K

Re: Factory Correct Restoration Details
 

Dave's questions are valid. I doubt the orange bracket is original.

It's very unlikely, knowing the production process. Engines were built in Flint or Tonawanda and the base engine was painted orange at that location.

Brackets were built at a local individual supplier and painted black at that point, or shipped bare and painted at the final vehicle assembly plant.

Engines were picked from the rack and hung on the "motor line" at the vehicle assembly plant, where they were trimmed out with the correct transmission, carburetor and accessory drive (including bracketry).

As a result - there is never a place in the production process where the engine accessory drive would be exposed to orange paint. Note that none of the factory photos of engines in the racks have the alternator bracket installed.

K

Re: Factory Correct Restoration Details
 

Always enjoy hearing how things were done from you Keith. For those of you who don't know Keith he is active on The Performance Year Pontiac board and his 6000 mile Royal Pontiac 65 GTO that his Dad raced is often used as a reference. He is extremely knowledgeable and a real asset to our hobby.

Re: Factory Correct Restoration Details
 

Thank you; fixed that for ya'

;)

K

Re: Factory Correct Restoration Details
 

What color should the AC bracket for a 72 be? (the one on top that bolts to the intake) How about the bottom AC bracket that bolts to the exhaust?

Mine appears to be painted orange (the top one at least). The adjustable bracket that connects to it also looks like it was orange.

Re: Factory Correct Restoration Details
 

I've had three factory AC trucks of 67-72 vintage and they had fan clutches. Obviously I didn't have them from new so don't know if they were factory equipped with them or not, but it seems to me that they would have been.

Re: Factory Correct Restoration Details
 

Sorry Keith, for some reason (old age) I had the wrong number stuck in my head.

Re: Factory Correct Restoration Details
 

The sets that I have cleaned up and restored appeared to have been factory black. There are seven pieces, if I remember correctly, to the truck AC brackets.

Re: Factory Correct Restoration Details
 

Black.

K

Re: Factory Correct Restoration Details
 

Keith et all,

Thanks for all of your comments and insight. Reading all of your stories is really interesting.

Here is a picture of my engine compartment before I rebuilt the 327 several years ago.

As I said previously, I can't say how my alternator bracket got to be orange. I checked all the date codes on my 327 and am convinced that all the major components are original and from around the same few weeks in the spring of 1968. The paint on the bracket was very hard and seemed original to me when I stripped it. (Not rattle-canned) There was no evidence of black paint underneath it.

I am pretty sure that I bought my truck from the original owner and there was no apparent repainting in the engine compartment.

As a child of the 60's and 70's, I do remember a day when used car dealers would re-paint engine blocks to make them appear extra clean and more saleable. This might explain why some engine components got to be the wrong color on some trucks.

I guess I envision some guy running to the engine paint line and handing the painter these previously back-ordered alternator brackets at the last minute with instructions to bolt them to the block and paint them with the block.:lol:

Re: Factory Correct Restoration Details
 

That top picture that Steve Haffner posted is very interesting to me as it is nearly a dead-ringer to my engine compartment. That also brings up another can of worms. The old Smog-pump vs heat riser question on 68's.

From what I can figure out 68's with automatics had heat risers and 68 manuals had smog pumps. I think there may be another set of rules for 3/4 tons and 1 ton trucks as perhaps they were not required to have emmissions controls. I am not sure though.

Re: Factory Correct Restoration Details
 

Re: Factory Correct Restoration Details
 

Interesting Burb71. Perhaps the Big blocks all got smog pumps regardless of the transmission.

Re: Factory Correct Restoration Details
 

. . . .

Here are the rest of the 68's I've saved . . .

You guys can figure it out !!!

The first one was said to be a 307.

The next two were said to be 327's.

. . . .