I don't know about "that didn't measure up to their usual quality" but I have a 6251 rod that has been sitting on the shelf for a long time that is no longer available.
I use the 6249 rod that is listed on their site as "3.287" Animal "Beefy" Limited Modified Rod with bearing inserts.
This rod has a thicker beam area to deal with the added stresses of a Limited Modified Animal. It is stock length and includes ARP bolts and bearing inserts"