Pondering either a Little M or Motown 400 block for my next project. Crank options are abound in the stroke that I'll be looking to get so the option comes down to what size mains to get, 400 or 350. Trying to get any information more from a durability standpoint. In a stock block application I'd probably want the 350 mains due to more meat in the webbing area, but thats probably a moot point on these aftermarket blocks, so from a crank perspective?? Thanks in advance.

 

if it were me i'd call c&a since that's most likely where my bearings would be coming from and ask them. just a WAG but i'd say you're splitting hairs unless you're trying to make every last bit of power you can. there should be no differance in reliability issues or how easily you can find parts. price may be a slight factor but you don't buy main bearings very often for that to really matter.

 

Just another guess, but the 2.45" mains (350 size) will probably be a little less expensive, allow a little less friction, and provide more options for crank material selection. Most 400 cranks are cast (there are some aftermarket forged cranks), but the window is open wide for 350 cranks in terms of material, strokes, and balance.