1966 273 Commando - Thoughts

you cant beat Cubic Inches.

You can add all the Commando/ Charger valve covers, intake carb etc and unless someone looks really hard will never know its a 360 based engine
Well, OP isn't trying to "beat" anybody... just have a rumbly cruiser.
And I know of a couple local 2.2s that regularly take down 5.7s- of both the LS and Hemi variety. Without nitrous.
But yeah, a 360 is the easy way out- I have a full dress "Sham-mando" in my '66 wagon. Not to pull ETs, but to pull a camper.