I have a 10C Atlanta SS that also has a PON frame, dated 10 16 65.

As to the squared off wheel well, without going into the parts books, I have always assumed that there was inner wheel house interchangeability between the Chevelle pass. models and the El Camino and wagons, the latter needing that space for routing of the gas tank fill tube.

Good Luck with the build!

Progress
 

Some update photos of the progress.

Date correct l78 962 block from another 66 chevelle built in Atlanta, along with square port heads, off to the machine shop after cleaning and a light coat of paint to prevent rust.

The frame before and after paint. Many hours of work just getting it to the 60mins it takes to paint.

Have been lucky finding alot of original paint and chalk marks all over the car. For example drive shift stripes.

Looks real nice. thanks for the update!

Please tell us you're putting the Keystones back on!

About 5 years ago, I had the opportunity to check out a disassembled '66 SS396 in Georgia that had the words "HOT ROD" written on the far right side, wrap-around area of the firewall. No doubt in my mind it was put there when the car was being built and was totally inaccessible & unreadable on an assembled car. Wish I could've gotten a photo but my cell phone was left in the truck!

Keystones!
 

In talking to the original owner it came with the mag wheel covers. I got lucky about a year ago and found a guy with an original set from a car that had less than a few weeks of drive time on them. Basically NOS. However im going with the painted steel wheels and dog dishes. Im thinking I would need my head examined if I did those keystones

Consider me one of the mentally deranged guys voting for the Keystones.
Day II rocks.

+1

If you are going to run hubcaps, I love the factory simulated wires on a '66. IMO, dog dish caps and simulated mag caps are overdone on restored '66 SS396 cars. Would be nice to see one with wire caps, or even the homely standard full wheel covers.

The keystones would be my first choice though (or cragars, torq thrusts, etc).

Really nice work, BTW!

I vote for the mag wheel caps!! Love those type hubcaps...

Keep at it Rick. Lookin Good!!

Mike