True statement. Magnumminded is also correct. While the 318 didn't take the compression hit the hi-po mills did, Mopar eased up on it, too. The 67-69 318 slugs sit highest in the bore @ .036, 70-71 @ .060, 72-86 @ .056.
IMO the difference may be a point or two in the CR, but if you're building on the cheap, why leave anything on the table you don't have to. If you're going to rebuild, check the bore to make sure you don't need to poke it out. Then get your engine rebuild kit. Specify a 67-69 piston in the appropriate bore.
The intake gasket set that comes with most rebuild kits will not work with the Performer (no experience with the Action +). The Eddie needs a slightly thicker, softer gasket.
IMO the motor is going to be busy & thirsty on a freeway with 3.91s and 14" tires.