Whats better,grinding a crank or line boring?

Eagle cranks come from China to...mine for my old 340 had to be cut .010/.010 right out of the box.....see if Mancini racing offers a Callie rotating assembly for your 400. Here's one they sell but they are using all Eagle parts, with clevite bearings and diamond forged pistons...

MANCINI - 400+.030" Stroker Kit - Internal Balance
Rod/Pin H-.990
$2,629.00
MRESTROKE-IKIT400

They have a 4.15 stroke Eagle forged crankshaft on sale for $399.00