Ok so is there a 2.0 twin-cam you could run on carbs and change the cam-cover writing - 432 like?
RB20DE? But, in that scenario, you may as well go for the RB25 for the extra bhp.
I have to admit, I hate the aesthetics of the Neo version of the 25. It looks cheesy. I'm sure additional horses could be released from the older version to make up the shortfall. There are high lift cams for the DE and even tubular headers, which have been modded before for Z use. It all depends on budget and aim though.