I'm 6'10" and like narrow cabs because I can still mount the seat further back and keep the cabinet behind the seat. If I had a wider cab like a cascadia or something like that, I'd have to remove the cabinet to be able to move the seat back 6" . We already don't have enough storage, so to lose a whole cabinet doesn't work for me...
A flat top 379 doesn't have much headroom in the sleeper. I am 6'2" and cannot stand up straight in a flat top. I have had one with a 63" and 48" sleeper. The 63" is probably more common with the older 379's. The closets are small and headroom is non existent. My wife used to travel with me sometimes when I owned the Pete with the 63" sleeper. She said it was like being in a cave. Those didn't have a window in the sleeper. But, you will look COOL!! It has been a quite a while since I owned a Peterbilt. I still like the look of a Pete. But, I don't know if I would buy another. KW has a much better designed sleeper. It depends on what you are looking for in a truck. If you are looking for a truck that has the best driver comforts and sleeper design, there are better options than Pete.
Go for the 387. My wife doesn't call it Moby $-$%+ its the big white whale... Go around truckstops during the day. Ask a driver if you can see how roomy the truck your looking for is. Like said before. Get in it. Drive it experience it. Talk is one thing get inside.
Hi king Q, LOL, always nice to start out at the top. (why not, this is America) I drove lot's of junk for years mostly because I was a local driver and Pete's and KW's were reserved for OTR. It wasn't until I bought my own Pete, then I was hooked.
I guess that's why I never upgraded cause hell I started at the top with a 359 flat top with a little CAT motor
I am 6'5" and have a 48" flat top its like crawling around in a tunnel lol, but you cant beat the classic styling
The 359 interior has a lot of practical uses. For example when I pick up a lot lizard or roadside bunny, if she can't fit between the seats to slip into the bunk it's probably better she doesn't go back there. I'll only regret it later.