Frame stenciling 1966

[Borje Persson]

I have just completed painting the frame on my 66 Convertible and according to some litterature that I have got, the painted number on the rear passenger side of the frame should read GM part number 3871317 and A.o.s number 303196 - 23 or - 24, -28, -29. Is there anyone that can tell me what the 23,24,28,29 stand for? Is there perhaps a reason for the different numbers, such as different production dates, Big block/Small block, Manual/Automatic tansmission??

I have also found some conflicting information about the color of the stencils, some sources indicate red stencil caracters some other White characterz.

Thanks for any information about these matters

Best Regards Borje

[Jack H.]

Re: Frame stenciling 1966

There are a number of good sources for information here. First and best is to put back exactly what was there before you did strip/dip/repaint. But, it's not always possible to recover the original marks based on prior owner chain (what did they do?) and specific conditions of the frame before you started.

The NCRS reference library in Cincinnatti has a nice book, "Corvette Chassis Restoration Guide" that goes into detail on the AO Smith frame componet as well as other related markings (inspector's marks on suspension, drive train, Etc.). The NCRS Judging Reference Manual, also available through Cincy, for your year car will tell you what factory concours judges look for on restored cars in terms of authenticity.

Last, vendors who specialize in offering marking products (Quanta is the first who comes to mind) will put together 'kits' based on the VIN # you give them to supply you with their best educated guess of the frame ID stencil and various paints/chaulks to recreate the chassis markings.

The dash numbers you refer to, if my memory serves me well, dealt with AO Smith assy line runs. Frames were built by AO Smith and shipped by rail to the St. Louis assy plant. Runs had a basis in time, but like many other components of the car, how the final assy plant controlled their inventory (LIFO, FIFO, just get it built somehow) makes the exact definition of 'correct' for a given car iffy.

So there's two answers here. If you just want to slap something down that will pass a factory concours judging and don't want to be bothered with the details, throw money at the job and call a vendor like Quanta. If you want to learn and experience the fun of understanding the various markings, you should invest in a support library and 'dive in' -- the second alternative is part of the fun and mystique of the hobby. GOOD LUCK with your car!!!

[Chuck G.]

Re: Frame stenciling 1966

Hello Borje: As I recall, the "suffix" numbers that you mention change when any modifications, even slight, are made to the frame. This is certainly true of solid axle Corvettes, and I'm fairly sure that it's true for midyear frames. I can't tell you what number belongs on your car. It would depend on the serial number/build date. Let's say that the first 63 frame was -1. The factory changed a few weld nuts, that became -2 and so on.....up until -24, -25, -26,etc. Maybe by 1967 they were in the -35 range. Others with more knowledge of your year Corvette might elaborate further. Chuck Gongloff

[Bill W.]

Re: Frame stenciling 1966

Hi Borje, You might be interested in Nolan Adam's COMPLETE CORVETTE RESTORATION AND TECHNICAL GUIDE,vol.2. It has great assembly line pictures for each of the mid years. Buy a magnifing glass and spend some time going over the section that interest you, it's avaliable through NCRS. Also, the numbers stenciled on your frame will be one inch "gothic", applied upside down. There will be a hand written date on the same of the frame. All this will be crystal clear when you see Nolen's book. Almost forgot, The frame numbers are in white. Good luck & have fun with your Corvette.