hehehe.....wheelie city & I hope you don't do much highway riding as your nads are going to vibtrate right off!
I experimented with going 2 teeth up in the rear and did not like the results of increased RPM and highway speeds, but most of my riding is done on the highway.
Increasing the rear sprocket by 3 teeth is the equilvilant of going down one tooth in the front. You have done almost double of what most do.
On a B-12, you may get by with a stock chain actually. I am not sure about a B-6. With 2 teeth up in the rear on my B-12 I used the stock chain length but was preety much at the minimum on the blocks. If I had gone down 1 in the front like you, the chain length would have been perfect.