273 commando Build

sure would appreciate it if some of you guys that built theses commando engines with stock heads and bore 3.625 to see what head gaskets you all used.. because the 318 gasket or larger will not seal.. that is my observation. that odd ball combustion chamber is limiting how much gasket material is available there for clamping . that's why is pushing that gasket out near the valley edge . it's only 3/8" wide . imo ... keep in mind this is no stock 273 it's built and is dialed in for max hp. it revs like it's on Nitrous with the lightest pressure on the Go pedal.