I tried this on another thread, but I think it was old so trying a new one. I am replacing the frame on my 1969 GS400 Stage 1 convertible. The replacement frame has numbers that do not mean anything to me, so please help. The numbers are faint in some areas so a couple of the numbers are a guess. 396 and then either (6 or 0), 7, s (with a circle around it), 291 Can you numbers gurus help me with this?

The S with a circle I recall stands for A.O. Smith, the company that made that frame. It makes items like water heaters today. A picture would help.

It appears you have a '70 frame. Boxed frame = convertible Open = Coupe All '70 frames start with 39607xx ( except the late BB frame) If open frame you need to do a little more cleaning to see at least the last digit of the whole number to determine if it is a SB or BB frame. Hope this helps, David

Thanks. It is a boxed frame for my convertible, all the bracing is correct for that. Your numbers follow what you have said about a 70 frame. I can see the 39607, but there is bare metal after that until the S in a circle. Then my 291 and bare metal again.