Who knows Detroits? 4-53, 6V-53, etc?

That would be fine if I could get one what I think is reasonable. Around here any cummins that the seller can convince himself "might run" is at least 3500 and in a truck 5K and up, running or not
Problem is that's about the going rate for one of those trucks. High mileage, body rotten off the frame, blown transmission, etc.. they still bring $2k and up.