I'm getting close to haveing every thing to put my 400 together. My pistons from Tim myers should be here today and plan on getting my rotating Assembly balanced next week. Do i need the fly wheel when I get it balanced if I do I'll need to get another one as I want to keep my truck running untill I'm ready to swap engines.

 

Honestly I'm not sure what for V8's might be internally balanced, but the 335 series - 351C, 400, and 351M are all externally balanced. When I had mine balanced they had to take s bunch of weight out because the TMeyer pistols are quite a bit lighter than stock.

They will need the entire rotating assembly from balanced to flywheel to balance.