Ok the DD blower is a roots blower it has lobes most bus people all they see are the 2 lobe type which is standard those lobes are not solid they are hollow made with thin aluminum with plugs in each end
When the engine spins so fast on a 8v71 it happens around 3800 to 4000 rpm it blows the plugs the lobes will swell and shuts the engine down I have saw this happen before on a bad buffer switch adjustment and no I didn't do the adjustment
90% of the time when one over revs above the limit it will cost you a blower not a engine they don't throw rod,pistons and debris all over the place as some visualize they may spin a bearing and most the time that doesn't even happen
Sometimes I wonder how GM and Detroit made the 8v71 without the help from the internet and a bus board
worry about other things geez