any option decoding secrets?

my 79 caprice coupe with 305v8 and 3spd auto is equip with every option other than the gage pack,sunroof and vinyl top. how do i figure out if i have the performance axle,ltd slip,HD suspension or sport suspension. it does have front and rear sway bars, and while stock, has a nice rake to it. any idea where build sheet might be, if there was one, i found my 73 chevelles under the seat in the springs

hotrodjunky1982 wrote:

my 79 caprice coupe with 305v8 and 3spd auto is equip with every option other than the gage pack,sunroof and vinyl top. how do i figure out if i have the performance axle,ltd slip,HD suspension or sport suspension. it does have front and rear sway bars, and while stock, has a nice rake to it. any idea where build sheet might be, if there was one, i found my 73 chevelles under the seat in the springs

This may help you. It didnt have my '87 Monte. It'll have all of your options listed for your VIN #

http://www.compnine.com/vid.php?vin=1G1BL53E3MW184575

Compnine only goes back to 1980, he has a '79. Unless the options changed in '80, he could look at his trunk tag and match the RPO codes to an '80 caprice.

Cadet57 wrote:

Compnine only goes back to 1980, he has a '79. Unless the options changed in '80, he could look at his trunk tag and match the RPO codes to an '80 caprice.

He could do that too. I didnt know it only goes back 30 years.

hotrodjunky1982 wrote:

my 79 caprice coupe with 305v8 and 3spd auto is equip with every option other than the gage pack,sunroof and vinyl top. how do i figure out if i have the performance axle,ltd slip,HD suspension or sport suspension. it does have front and rear sway bars, and while stock, has a nice rake to it. any idea where build sheet might be, if there was one, i found my 73 chevelles under the seat in the springs

The first thing to look for is an SPID (service parts identification label) sticker under the inside of the trunk lid. If it is the correct one for your car, it will have everything about that car, except what the GM assembly line worker who installed the steering wheel had for breakfast that morning. Those RPOs (regular production options) will state every thing about the car including the rear axle ratio & open or "posi" status. If you look on the axle tube itself there is a code that indicates even more, and that should be on the passenger side tube usually facing toward the front. Unless of course it is rusted beyond being readable, but usually if you use a mechanics wire brush and rub that area, you can salvage the build info.

Things like springs always have some white paper tag with two black letters indicating what the factory computers determined to be the correct coil spring. The build sheets are often between the wave springs and the foam cushion visible under the seat after you remove them from the car. You don't need tools to remove the back seat bottom and you can see a good portion of the upright seat from inside the open trunk with a flashlight. At this stage, those paper sheets are fragile, flakey and usually rust stained and/or ripped.

If you wind up with NO readable numbers, all is not lost because most components can be identified, however if the point is to restore the car authentically back to original stock condition, you will be lacking. There are some sites on the internet that decode VINs for free, but your car's age may hinder those efforts. I believe that anybody who tracks down the original factory service manual for their year & model car shall benefit greatly.

If you clean your rear axle from a build up of rust, be care not to get too aggressive with coarse sandpaper because you want to SAVE the faint rust ravaged stamped alfa-numeric codes, not obliterate them. There are also two more codes stamped on your engine most likely on a deck pad in front of the passenger side cylinder head. Also look for a body number plate under the hood attached to the cowl area I think, it will have paint, trim & seat codes etc. Happy hunting!

thank you

the rear seat just pulls out? no clips or screws to break.

hotrodjunky1982 wrote:

the rear seat just pulls out? no clips or screws to break.

Climb in behind the front seat backs, you will be facing to the rear, Push down on the seat with you hands while using your knee to firmly force the seat frame at the bottom from its rearward facing floor mounted hooks and then pull up and toward the front. When its out you will smile at the simplicity of it. For the top, I will I assume that it is the same as all 6 of my 88-90 9C1s, then you will have to remove the two seat belt securement bolts and then slide the seat up about two inches and it will be free.

what do u know about front suspension upgrades?

hotrodjunky1982 wrote:

what do u know about front suspension upgrades?

Don't do what I do. Try to put those questions in/under the correct topic heading so we don't have to chase you all over the place. BTW, Welcome aboard!

no build sheets under the seat, trunk tag gone, its just an outline in the paint.

hotrodjunky1982 wrote:

no build sheets under the seat, trunk tag gone, its just an outline in the paint.

It probably got painted over. That sucks. Maybe try to lightly thin the paint over it?

1984twodoor wrote:

hotrodjunky1982 wrote:

no build sheets under the seat, trunk tag gone, its just an outline in the paint.

It probably got painted over. That sucks. Maybe try to lightly thin the paint over it?

Before messing with that painted over SPID tag, I would stop and wait to hear a few suggestions from the guys who know their way around body shop paint materials and solvents. It may be a simple thing to get done with the proper "know-how".

You might test the paint nearby with solvents to see which ones work. And then find an SPID sticker on some GM car you don't care about, and see if it does NOT dissolve that as well!

Or you might be VERY careful and wet-sand VERY slowly to get down to where the paint is faint enough to see through.

What color is the over paint? I hope its white or some very light color.

it was scraped off in 1980,just the outline

hotrodjunky1982 wrote:

it was scraped off in 1980,just the outline

Oh, Gladiolus!

Not to worry though. Every component is ultimately identifiable, as long as the goal here is not to restore the car back to its truthfully original condition.

truthfully, its as original as it gets

It's for 1981, but maybe some of the options are the same:

http://www.gmheritagecenter.com/gm-heritage-archive/docs/Impala/1981-Chevrolet-Impala.pdf

You can also order copies of the build sheets and factory invoices:

http://www.gmmediaarchive.com/
http://www.gmmediaarchive.com/?page=2

Cadet57 wrote:

It's for 1981, but maybe some of the options are the same:

http://www.gmheritagecenter.com/gm-heritage-archive/docs/Impala/1981-Chevrolet-Impala.pdf

You can also order copies of the build sheets and factory invoices:

http://www.gmmediaarchive.com/
http://www.gmmediaarchive.com/?page=2

Thanks Cadet57, I had heard about that site but I finally got the time to really check it out. Prices seem steep, though: $50 for each item. (copies)

Being an old timer that owned a LOT of bow-ties over the years, I must confess to getting lost in there for a whole day just researching and reminiscing.

I dug a little deeper at gmheritagecenter and found this . . . http://www.gmheritagecenter.com/gm-heritage-archive/docs/Chevrolet/1979-Chevrolet.pdf .

HRJ82, Check your pm. Also, I tentatively worked out a very affordable game plan for your asked for improvements.

I will look for your return to that thread to pick it up from there.

are they blank reproductions, or my specific vehicle?

hotrodjunky1982 wrote:

are they blank reproductions, or my specific vehicle?

You can identify every component on your car the old fashioned way and determine if each part was an option or base model inclusion to your specific year and model.

With out the SPID or build sheet, you will not know for certain if that was how YOUR particular car was ACTUALLY assembled "way back when".

I do not know how original you want to make your car. But, with that link, at least you can insure that it will be a car that COULD have been built that way.

You could NOT pass the car off as an original survivor if it had a L88 motor with a T56 behind it.

Did you get to check on the rear axle for it's alfa-numeric code?

I do NOT know if the heritage people are able to break down your vin to the actual RPOs like Compnine.com does. I DO hope you get at least that for your $50.00!

If you had a coil spring missing it's 2 or 3 letter tag, you could measure it's wire length, wire dia, # of coils, free length etc and with that info, match it to the data there!

suppose ill crawl under on monday. with the release of the phm article on 77-90 caprice, stock might be the way to keep it

hotrodjunky1982 wrote:

suppose ill crawl under on monday. with the release of the phm article on 77-90 caprice, stock might be the way to keep it

I like that. Bolt-on improvements that are 100% reversible are always a smart choice with vintage cars like yours.

Just make sure you document, tag and save all items removed from the car.

this resto has full documentation, dvd, pics everything labeled, wish i could upload that.

hotrodjunky1982 wrote:

this resto has full documentation, dvd, pics everything labeled, wish i could upload that.

I would like to see that documentation. A lot of people here would as well.

Since I am no whiz with computers, and I was able to load my photos here, then you should certainly have no more difficulty than I had.

Pretty sure you need to do this through an image hosting site such as Photobucket, Imageshack or Smugmug.

I assume that you have viewed all this info on your computer already. For me, putting the photos up turned out to be easier than expected.

If there are any computer savvy members out there, hopefully they can advise you on how to get it done. I asked for help, and it came.