I have a very early production 1966 convertible that was built on September 10th 1965 . That day was a Friday and the 7th calendar day of production for the 1966 model year. Could Chevy have used a very late production 1965 chassis to build this 1966 model year car ?

 

I cant say this with absolute certainty but I dont think there were any changes in the frames from 65 to 66.
However if the frame on your 66 is original to the car there will be a serial number matching your cars number on top surface of the frame located on the drivers side kick up.

 

Motor trans and rear are all correct matching #'s.

What prompted my question is the rear trailering arm bumper mount looks like a 1965.

It does have the slots in the frame for the 1st year 1965 side exhaust.

 

Sounds like a doner frame dosen't it? Someone had a bad frame and transplanted the drivetrain and body on the replacement frame.

 

I would say it is not the original frame because from the beginning of the model year of 1966 they moved the brake line that runs from front to back to the side of the frame instead of the top so the center crossmember is notched differently than a 65 frame to accommodate the brake line. There is no difference in the bumper bracket for the trailing arms between 65 and 66 the change was between 64 and 65.

 

Thank you all for the information. My search for a 66 chassis begins now.