My idea is to try a Novak 5.5 Lite with GTB in my BJ4 with 4 x 4200 cells.
I will try a FDR of around 9.75, 78 spur with 20 pinion.
I will temp gauge it after 5 minutes and maybe decide to gear up more.
If i ran my B4 i would probably use the same gear and ratios.
How does this sound?