I just replaced my 94 CTD w/ an 08 4500. Old faithful spent 14 yrs at 12,000 lbs pulling 15,000 lbs trailers. The only problems were the KDP and clutches w/3. 55 rears. The new truck is a 6sp manual, 4wd w/4. 10 rears. It weighs 11,750 w/all tools onboard. I'm very happy with it so far except for the speed limiter.