Just to clarify , the disc never gets balanced except by the manufacture. It is balanced to neutral .I'm not a small block guy but I thought the 340 was a internally balanced engine. I know the 360 was externally balanced. Are you sure what engine you have?
This is wrong. I have an arbor and I balance EVERY disc. Most discs are off 8-10 grams.
Most shops don't do the disc and it really can be picking the pepper out of the fly poop.
To the OP...is this a Borg & Beck or Borg & Beck/Long cover?
If so. I have a hard time believing McLeod didn't replace the cover. Those covers are heat treated and if you weld on them it will FAIL, and you can bank on that.
Welding a washer on the PP is a piss poor way to balance it. You can drill the spring stands or use press in weights and get it close and then take the rest out of the FW.
It is a balanced ASSEMBLY.
