Is this a hemi block?

[Gus chiggins]

View attachment 1570608
O-Ringing provides the ultimate seal on head gaskets. Especially before MLS gaskets were introduced.

Isn't o ringing done on supercharged, or turbo engines, no?

 

[33 IMP]

Isn't o ringing done on supercharged, or turbo engines, no?

O-ringing is used generally for very high compression engines , whether from static compression (15 to 1) or boost, from whatever source.

 

[MiradaMegaCab]

Isn't o ringing done on supercharged, or turbo engines, no?

Yes, and with Nitrous Oxide as all of these will increase cylinder pressure.
I run O-Ringed heads with receiver grooves cut in the block and SCE Copper HeadGaskets on a blown Mopar SB with Nitrous. This was the only way to hold a head gasket together 30 years ago on a SB. Gasket technology has came a long way since then.

 

[RemCharger]

The block appears to be relieved and deshrouded for the intake valve.