Another thing about 6" rods in a sbc is that it can become an internally balanced rotating assembly without adding heavy metal to the crank, at least it was for my Scat crank/rod assembly.
A lot less load on the front of the crank & #1 main bearing by using a neutral balanced dampner instead of the offset weighted type normaly used with 5.7" rods.
What alot of people would point out is that a 6" rod requires the use of a piston with the pin location raised closer to the top of the piston. This reduces the amount of room for the rings. Most but not all pistons for a 6" rod
have the pin hole intersecting the oil ring grove requiring an oil ring support rail.
I know of at least one piston that doesn't have the piston pin hole intersecting the oil ring groove, but it uses 1.5mm rings and is fairly expensive for a set($650). Mahle PN SBC125040F05 for 0.040" overbore.
High quality works of art IMO.