Ok, long story short, wifey is wanting to trade her car for a 6.4. One is an 08 250 CCSB KR 200k "bone stock". Other is CCLB 450 DRW with 180k. DPF and egr have fallen off. Both look like nice trucks. I'm 7.3 and 6.0 savvy but clueless on a 6.4. What do I need to look for? I have AE so that will...