Spark plug choice

[Minority]

When getting a new plug for the Lambretta the other day, I was looking at the NGK info at the auto store and later on the web. I have normally used the B8ES (well now BR8ES since I fitted the SIP speedo), but in the NGK info it suggested that using a BP8ES you should get a better flame front and more efficient combustion. http://www.ngk.com.au/spark-plugs/techn ... projection http://www.ngk.com.au/frequently-asked- ... rs-signify (and we all want that little bit more don't we ). Now as I am using a standard side squish/side plug AF head there seems no chance of the slightly taller (1.5-2mm) ground electrode being hit by the piston (could be more of a concern on a center plug head?).
I was wondering if anyone had used a "P" type plug and if they found any problems/benefits?

[warts]

If that's a swop from a normal plug to an extended nose plug then you may have to retard the ignition. The flame front has less distance to travel.
Only piston I ever buggered up (on my own vehicle) was inadvisedly swopping over to extended nose plugs while crossing the Hindu Kush.