That is too bad.
Those pistons will probably give you 7.5 - 8.0 compression.

I would not run them, but that's up to you.

You should be able to get the correct pistons w/out that big chamfer.

I personally had used those same style pistons but were forged TRW's. At the time (I was young) I had told a shop to order me 307 high compression flat top TRW forged pistons, well, they did not, I got stuck with running those pistons & was really disappointed in the engine output, sluggish throttle response etc.

Part of the reason I tried all those different manifolds, 2 & 4 bbl carbs, carb spacers etc, trying to get the combo to work, well it didn't.

It did not run good until I installed the correct 307 flat tops, then I was over 10:1 compression. My head had been shaved/milled/surfaced.

Those knuckle heads did not know anything about how to get an inline 6 to run good.
I was young & ignorant, lesson learned.

MBHD

12 port SDS EFI