273 Commando Engine Clone

With the head gaskets bore size available today there no issue running the 10.5 pistons, you can only get around 9.2 or so out of it.
Been running mine for 3 years now with no problem or detonation issues, on 87 pump gas only.

I usually go the other route. I use the 2 barrel flat top pistons and mill the heads to get where I want to be. Most of my cars run premium gas anyway so I'm used to the extra expense.