I don't happen to know it, but I just checked for you.
B for the upper front arm is 30mm
Eye 2 Eye for the front hubs is ~44mm
It's indeed a pain to try and fit stuff together without being able to actually fit and see what's what. If you need more measurements just keep asking ;).
Mugen MBX6Te RCM + Mugen MBX6e RCM + Savage Flux XL FLM + MERV all with Spectrum DX3S || WTS&WTB