273 power? HOW?
'64 - '65 and '66 -'67 LA heads have one of the smallest if not the smallest combustion chamber of all the LA heads. Plus your 2bbl 273 should be right at 9:1 and if you want to run regular you don't want to go any higher. I had a 273 in a '69 Fury and just by putting on a Performer intake, 600 Holley and headers with duals the thing ran real well. As a matter of fact the car is long gone but I still have the motor I was so impressed with it. Next stop for that little 273 is in my '85 Cherokee XJ. If you motor needs a complete rebuild it will probably cost you more doing the 273 that doing a 318 or 360 because the pistons are harder to get and are more expensive.
Chuck