Hello all. I've been in the back ground on here and other 6.5 forums for months just reading post and learning. Now I have run into some problems I need a new 6.5TD engine, and have been looking at the optimizer. The p400 is out the question cause there aren't available, and I cant wait I need my truck. So the questions I have are, about how much is a fair price for a long block, and where to get a REALLY AUTHENTIC ONE(not a overseas one). I have talk to Leroy Diesel, and the time frame is way to long at this time. Please ANY info will help. I Love my truck and this would be the first summer with her, help me get her back to her glory. THANKS IN ADVACNE EVERYONE.