I see some engine have balance shafts. I was just calling around about getting a rebuild. I thought the core I have was bad because the balance shaft through the back bearing and destroyed that area. To save a $500 core charge I called a builder to see if the core was rebuildable. He said they don't put balance shafts in so the core is good. He said "they found that the engine runs better and more reliable. Also Improved timing and oil pump helps". What do you all think? I wonder why they put the shafts in?
