I looked at a 69 z28 this weekend. It is an 01c build car with x33 coded car. The car is just a shell. A few things I found that was odd that I am not sure could be correct is that the brake valve on the subframe below the drivers seat area is not there. The other thing is I found the crayone mark on the rear seat near the passenfers side package tray was marked DG I am sure of the D but the G could be a C maybe? Has anyone seen this? I thought it should have been X3?

Thanks

I have seen DG = Dark Green (Fathom Green).

The brake line valve on the LH frame rail has nothing to do with Z/28, SS or any other HP option. Some drum brake cars have it. It is nearly always found on front disc brake cars from early calendar year '69 on; front disc cars built before that usually do not have it.

With the original VIN-stamped engine missing the only way this car could be verified as a Z/28 would be genuine original paperwork. Nobody trusts body tags any more. 12 bolt axles, Muncie 4-speeds and dual exhausts are not unique to Z/28 and can be easily added.

William makes some good points, but Z/28s had several unique features that not all cars had. If we only relied on paperwork, and paperwork alone,or a VIN matching engine, then we'd all lose out on alot of really nice 69 Zs.

Cowl tag-
There are the cowl tags (fakes can easily be spotted,so I think they can still be relied upon as a good starting point, especially those with X-codes that are within the VIN range of the car).

Speedo Cable-

Z/28s will have the speedo cable exiting the passenger side of the brake booster for the Muncie trans.

12 bolt-

The codes on the 12 bolt are also very telling. The default was a BU,3:73 ratio. My car was late (10C), and is actually a CBU code, a rear that was shared with other cars, but is correct for a late Z.

Fuel Line-
Single fuel line- Yes even base cars had it, but original dual lines means its not a Z.

Disc brakes-
All Zs had front discs. Look for the correct brackets on the a-frames for the brake lines. Z/28s also all had quick ratio steering. A manual steering car would have the 6 inch (5.75) Pitman arm,and short steering knuckles.

Cowl Paint-

If you are fortunate enough to find it, a z had the cowl area painted the same color as the stripes. This was so that it matched up when looking through the cowl vent from the top.

Trans-
All four speeds, so check for pedals,and correct 4 speed hole in tunnel (if it was not hacked like most)

Bulkhead marking-

X3 or X7 for X33 or X7 respectively

Mine was late car, and as such had the brake valve under the driver's seat area.

Clues abound on these cars. Yes some of these can be easily duplicated, but when you find things like the original GM lacquer just under the surface,and all of the clues above,chances are very high that its a Z.

As for cowl tags, yes they can be forged,but luckily stand out for what they are. Apparently POPS and paperwork are now being forged, so they are no longer 100% reliable either.

The upshot is, look at the car, and figure out if its a Z. Thats better than any trim tag or paperwork IMO. Jerry M can verify them through his expertise. If you get serious on buying a car, he's a great resource to use if there are doubts.

Another quick check is (and I'm sure I will be told if wrong) is all Z's had quick ratio front steering which meant that the pitman arm is the longer 5.75". A item that most clones don't add.

All SS and Z28 power steering cars had quick ratio steering which had the 5.75" long pitman arm and short steering arms on the wheels. The option was N40/N44. Other cars had to order both options. Non power steering Z28's (and maybe SS's) had the same 5.75" pitman arm and the shorter steering arms. A normal manual steering setup used on Non Z28s has the shorter pitman arm, and longer steering arms. The quick ratio manual steering option that was available on Z28's has a different sector gear inside the steering gear housing. You can not tell a manual steering gear is quick ratio or not, by looking at it.

Well said Bob.

BTW: My Fathom Green/Dark Green Z had DG behind the seat, no X.

Haven't some of the cars w/o an "X" been discussed? Seems like a dark green car without the "X" would have DG3 or DG7 for a Z. If it is DG1, then it is probably an X11 car, correct?

on my car i have dg3, but the dg stands for dark green interior