The difference is not just 1/4" since your pedal strikes when the bike is at an angle, not standing up straight.

Narrower pedals help alleviate pedal strike. Don't use BMX platforms or touring pedals and make turns using common sense. I wouldn't go with 165s if you intend to use the bike for the street mostly. They will make you lose much-appreciated leverage. I also find that vintage 165 cranks are more expensive, so I just buy the 170s, haha.