O-RING ON CYL HEADS

[RSM]

I AM BUYING SOME HEADS THAT ARE O-RINGED, WILL THIS BE A PROBLEM ON A BLOCK THAT IS NOT O-RINGED OR DOES THE BLOCK NEED TO BE O-RINGED ALSO TO MATCH. CAN THE O-RING BE WELDED UP ON HEAD THEN MACHINED DOWN.

[a13badazztoys]

Are the heads aluminium?? :?: