I bought an ‘02 duramax with 220k miles. It had a fuel knock for who knows how long. I drove it for about 200 miles until this happened... I was going about 50mph and the fuel knock all of a sudden got EXTREMELY loud. I pulled over and parked it and blue smoke started pouring out of the exhaust. I shut it off, started it back up... still smoking. Decided to continue driving it home for another 30 miles. The noise quieted back down within a few minutes to its original knocking sound. The #8 injector balance rate was reading high (7.5). Decided to put new injectors in. With the new injectors in, the noise pretty much went away except you can hear a very slight knock... checked compression and it’s reading 200 in that one cylinder. Is it worth diving into and spending more money trying to save the engine? Or is there too much damage done? What could be damaged. Not sure if I should take my losses or try and repair it. Thank you!