Agreed. If you are making a torque monster, then generally, RPM is not where you make power. It also makes a more comfortable round the town car, which it sounds like is your aim. Takes a few corners, let it rip for half a block etc. Maybe you can smoke some tires, which would be something on a 240z.
I have to say that lowrider's idea of using a micrometer is intriguing. I have never used them but I would probably buy a set if I were doing what you are doing, just because. And can never have enough tools to play with.
Testing the crank for trueness seems like a good idea. A machinist can throw it on a lathe and find this out in about 1 minute.