So I'm new to the diesel world. My last Silverado was totaled and I'm looking to buy my first diesel. A friend of mine is selling a 2006 Duramax LLY. Extended cab long bed. Fully loaded, Allison trans, fully rebuilt engine with a ton of new parts EFILIVE tuning etc. no rust at all. . Around 230K on it and wants 9k. I'm slightly mechanically inclined but don't know everything. What should I know going I to it before buying? The truck seems in top condition. And the price seems good. Will the trans hold up with all the mileage? Is it a reliable truck? Please help me out!