Peterbilt 589

That’s because you’re looking at 2 different cab styles. The 387 is their first wide cab, later changed to the 587. So of course the dash and interior of a 387 will be different than the rest of the 3 series. The 3 series cab that the 367, 378, 379, 386, 389, etc used all shared the same common cab and interior.

 

My last truck spent the first 240k of its life with a lift axle grossing 105k in the mountains. I bought it and pulled the axle off, pulled pneumatic and hopper with it and a little bit of dry van. I sold it over 2 years ago with 600k on it. Current owner put the lift axle back on it and has been pulling a 3 axle milk trailer since. It’s still somewhat local to me and as far as I know nothing has been done to it. It was just under 1200rpm at 65.

 

The 387/587 was short lived, like the KW T2000/T700.