I realize that by not grinding it, the crank will be as strong as it can be. But I am not hearing of anyone breaking the stock cranks.

I will be spraying around 200-300.

Should I mess with the crank, trying to gain cubes, or should I leave it alone?

 

as long as the machine shop doing the grinding puts a good radius on it and does it right there should not be any problems. you would have to get a smaller jurnal rod like a SBC 2.00" and you will also need a custom piston. then every thing will need to be balanced and you should be fine. as you can see it gets expensive and almost not worth the extra cubes but if you plan on using alot of nitrous then you will be benefiting mainly from the new forged pistons and better rods then stock.