well there are quite a few sites that have 2.3L racing parts for NA engines, there is a circiut where i am from that runs 2.3L mustangs and 4 banger chevettes around a dirt track. they have cams, pistons, rods and all that for the cars, just gotta start looking.
why not just put a 2.5L in place? it's just a different head and EFI. or take a 2.5L short block and swap the head from your 2.3L.
or just take the crank from the 2.5L and stuff it in your 2.3L
making it a 2.5 or 2.4 (just going by memory)
and of course you could always take it to a machine shop to be punched out .030",
but other than all that work why not just get a bigger engine?