I use Bosch super 4's in my B6254, whole different generation of engine though I suppose.
The standard Volvo jobbies I took out had a 3 way electrode anyway.
Anyway, these tend to generate a good spark as thers's 4 electrodes to choose from!
Although I must admit, years ago I condemmed an engine in my Escort after a super 4 failed. Only clocked when I swapped them over to the engine I got from a scrappers: "I might aswell put them in, they've only done about a thousand miles, if that!!" Low and behold, new engine running on 3 aswell... DOH!!
HTH
Steve