273 time to 'fish or cut bait'...

Just to be sure, what are the numbers on the heads? Yes as mentioned, think about what you need and form a plan. Did the car you want to build come with a Commando engine? Are you interested in restoring it to original or do you want to build a 4 barrel engine just because you own one. If you are not restoring the car you could put in a 318/340/360 if you want more power. They all cost about the same to build if you are going to freshen one up. The 273 may cost a slight bit more because of the harder to get pistons. Really there is nothing wrong with a 273 unless you crave lots of tire smoking power (and along with that "usually" comes worse gas mileage.) My 273-4bbl. with a 4 speed and 3:23 rear gear is fun to drive and gets 18-19mpg on the highway. Click the link below for my 273 build thread.