Originally Posted by 94eg!
Not really cause wider suspension blocks are used in conjunction with short arms to maintain the same overall width...
If you compare two cars that both came with long-arms and different hubs (MSXX vs original 416), the 416 uses 2mm shorter driveshafts. I was always told this is because of the longer axles...
My bad, you are correct. I ended up putting 46mm bones up front on my 416. But you do not need 44mm on the 415 or 416 up front. My 415MRE has 46mm bones front and rear with long arms and 416 hubs, carriers, spindles, and axles. No problems.
And yes, suspension blocks do play a role in bone length. Remember, they go all the way down to XD if I remember correctly. So if you narrow your car way down with 46mm bones, you may need to switch to 44mm bones as not to bind in the diff or spool/oneway. That's why I added and/or to the equation.
In short, if using long arms, 46mm bones are fine front and rear on a 415MRE. If using short arms, you will need 44mm in the rear, and either 44mm or 46mm depending on suspension blocks. Common setup C/C or D/D you can get away with 46mm front.