273, or 318?

Make up a parts/machining list for both 273 and 318. You will be surprised how pricey the 318 can get.
I was looking to do the same thing for our 67 cuda. With varying piston weights you could be into a "rebalance". Up here that's approx $600.
Is the 273 2 or 4 barrel?
Egge and is it Canton/Kanter make the Commando pistons.
There was a member on here about 4/5 years ago that did a drive by here that mentioned he bought some Commando pistons, but no reviews from him.
Good luck