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

Modern cam will more than make up for the 9.5:1 power you'll get with Egge 4V pistons. A cylinder bore job will require oversized pistons and rings, AND a balance if the pistons are not replacement weights. 273's liked to rev, thats where the power was. They used the same heads as the 318 so HP potential is the same but at a higher RPM than the 318. Your car show buddies wont know the difference between a 273 or a 416 CID stroked 360 by looks alone. Dont expect the 273 to pull hard from a light and cruise at 80, its just not that flexible in that size. You might consider an Over Drive trans from a later Mopar. That would give you a higher top end without destroying your low end, but itll have a pretty wide ratio.