Are all 273 V8's the same?

Oldmanmopar said

I could see one or two. But all of the commando cars here have flat tops. Even this never touched car from the original owner. Could it be a 66 thing or a 4 speed thing. All of the cars here are 67 autos.

One original engine was removed and stored by the owner after installing a 340. it came with the yellow car. I have all the pistons Not one domed. I lost count of how many 273 commandos Todd and I have here. It would be mind blowing for someone to remove all the domed pistons from the engines here. These are commando cars and one Formula S coupe. All of them are E code

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1st are those original pistons, or aftermarket? They look aftermarket. Oversize? For a long time 10.5:1 pistons were only available as custom. I've bought and parted a 67 Formula S in the 70's with 50,000 miles on it. It had domed pistons, I still have it. My 66 Formula S had domed pistons. I bought a virgin 273 Commando motor and trans from a member in the 80's it had domed pistons. Check an old Motors Manual or tune up guide from back in the day, they will list the Commando/Charger 273's compression ratio as 10.5:1. The 2 barrel motors will be listed as just under 9:1. The D Dart was so rare, most people do not know about it. Probably only 50 or so, but I do not know the number.