Gave my B03 it's first official race day yesterday, with around 23 tanks of run in and gentle (and not so gentle) bedding in.

Very impressed by this motor on the track.
I was running a 6.5 restrictor, GO EFRA 2072 pipe and header, O'Donnell 97T med plug and 25% fuel.
The 2072 pipe was a wonderful match, giving very strong (but smooth) bottom and midrange power plus insane top end, which was never really fully exploited due to running out of straight
On top of the power and drivability came some excellent run times.
In casual practice with the above set up we returned tanks times of 12.17 and 12.52 in my X-Ray 808 buggy. The 12.52 is a little innacurate as I had several brain fades and ended up on my roof a few times.
Race pace tanks of 11 min would be quite possible, and 10 min - 10.30 easily attainable with this set up.
I have some 6mm Tecnopower restrictors on order, and there is more than enough power on tap to run the slightly smaller 6mm restrictor and still have all the power and top end you would require for most tracks (in buggy), while increasing smoothness and run time even further.
The three of us running the motors yesterday (2 x BO3's and 1 x B02T) managed 2nd, 3rd and 4th in the A final, so a very nice introduction for the brand into the local race scene here. Not one glitch or flame out all day.
My B03 temped at 120 C after the 30 min final, and on inspection the glow plug was mint. Golden brown and slightly damp, with the coil a nice silvery grey and no distortion. Pretty much what you are looking for, confirming the motor was giving those run times without being run too lean.
Thanks for a wicked motor Rody