273 for early A

Looks good. That cam looks close to a 340 cam. We used to run the 340 cam in 273's and 318's all the time. Use a windage tray. I'd run flat top 2 barrel pistons if it were me, you may only find 91 octane here and there. 3.23's will get you around 20 mpg cruising to Arizona. 2.76's are the go to highway gears and you should get over 20mpg, but the fun factor goes down unless you are into highway flying. What other parts do you have for the 273 on hand?