273 Comando Head ??

clifftt said

Good luck finding a smaller gasket. It's been documented here many times the small gasket is not manufactured by the large vendors anymore. You will either use the larger diameter gasket or pay big bucks to have one custom made by Cometic. Mopar makes a thin gasket which will help to keep your CR up.

Click to expand...

When it comes to the 273 ...
When ordering custom head gasket bore size...note the chamber are usually a hair bigger than the actuall 3.65 bore possibly because they were already in the works for the 318la predecessor... either way the chambers are already bigger than the bore by a notable amount and a gasket too close to the actual 3.65 bore size could hang into the chamber once installed and act like a step/stair case into the bore.

So measure the chamber width across the valve center, they are closer to 3.8" +inches