I currently have a 96 k3500 it has the 6.5 turbo this rig has 508000 on the clock and nothing major has been done to it aside from ip and timing chain water pump. I pull hard I have a 38 foot travel trailier weighs in at 14000 pounds. The truck pulls it ok with mpg at 7 to 8 and pulling at 55 to 60 temps while pulling run around 205 to 210 and egt runs around 800 the engine is starting to show blow by and my little voice is saying time to replace. Forgot to mention injectors replaced every 110000. My question is would it be wise to get the optimizer or just get a used engine with decent warranty. I use this rig daily and pull other trailers so I need the same dependablty ive had to this point