Taking a carbide to the front crank pin arm to remove weight will only weaken it. I understand that the ballast cast into the rod caps are meant for balance, but not to be removed almost completely. The crank(AFAIK) wasn't meant to be balanced at 50%, which it why the bob weights are not as large as an aftermarket piece. IMO, this was a hack job, the person who performed the balance clearly showed that they didn't know these engines were balanced at 36.6%. I also feel that the weld job was not acceptable, I really don't feel that is safe with cast iron, especially to pile that much material in one spot and all the heat. Welding on the flex plate along the ring gear is a hack job, they could have at least added a weight instead of blobs of weld.nothing in that engine looks too out of the ordinary for a rebuild.. cranks get welded on and rods get ground on to balance things.. sometimes a single rod is replaced with one that looks different than the rest but is functionally identical. the only part i don't really care for is adding weight to the flexplate, which only serves to make life more difficult if you ever need to replace it for whatever reason..
honestly, i'd take everything in to a machine shop and have it looked at. maybe get the balance redone with a different flexplate.
The would be me and the shops name is VA Speed in Virginia Beach. I put pics all over the facebook page. It is not my car. Hopefully we can get it right for him.There is always someone who has it worse. Don't know his name here but poor guy had some shop(VA perf?) hack up his engine very similar to this, except much more errors and hacks. Fully forged internals, lots of expensive parts.
PM'dHave you spoked with the previous owner on this issue? I know you bought it last year, but it looks like he screwed you. Is he still a member here?