I wouldn't be so quick to conclude that. I don't mind when someone that really knows their stuff is confident in what he does and has the results to prove it. I also had a 1969 Hemi Road Runner with 38K miles on it that ran well too, although that is California temperatures, not the below zero experiences of back East. My engine rebuilding guy (my Hemi didn't need his skills though, as it was fine at the low mileage still) is somewhat the same way, and he specializes in the 426 Hemi rebuilds. His attention to detail is amazing. I like that, and I don't care if he comes across as overly confident. He has earned it.