1920 5turn+2 or 3s 8000's will it be faster than 4.5?

[Thunderbruiser]

i think imma go with a 1920 6 or 7t still deciding and a quark 125 or so for the controller....where can i buy a 4mm size pinion

[Gustav]

I thought Mike has some 4mm pinions,if not then get someone with a lathe (such as Mike)to run a 4mm drill through some 1/8 pinions,i do that to run 48p pinions on my 1920,there's still plenty of meat left on them since you're only increasing the diameter by less than 1 mm.