273 crank in 318 bennifts??

I'm surprised none of the guru's here have touched on the key reason why one would use a 273 crankshaft over a 340 or 318 crank. The 273 crankshaft's are quite a bit lighter. The only downside is that they also have a smaller pilot hole for the converter's snout. Still, it's worth it to use a 273 crank as it's not a real problem to have a converter snout turned down to fit the 273 cranks pilot hole or... get the right converter the first time.

I remember the first time I used a 273 crank in a 340. The motor was assembled and on the running stand and had been broke in and I was ready to rock and roll! Race day was almost upon us and all's we were waiting on was the converter to arrive so we could mate the transmission to the motor and stab her in the car... to my dismay the converter's snout was too big! Luckily I give my machinist BJs every so often (not really), so he went ahead and turned the converter's snout down to fit the 273 pilot hole before the night was over.

Edit: Oops apparently RustyRatRod already touched on the weight difference.