N14 running 1800@ 75 mph

Great way to ask a question. Call people names......

 

you can run a diesel at max rpms forever,will not hurt anything.just burn fuel

 

Seeing as most have a sticker on the engine that says "XYZ HP@2100RPM", I'd say you are safe.

Martin

 

It's old, but that is how they were set up, years ago we ran 903 cummins at 2600 rpm.

i don't think you can find a13 speed direct and that would no lower your rpm's a 13 over would drop your rpm by quite a bit. Eaton has a calculator on their site that will let you figure it out,

 

The 855 blocks ran great at 1800-1900 rpms all day. They run cooler and get better mileage. Last thing you wanna do is lug it. Keep it pumped up it can take it. It will never run like a 550 cat, you can do some tuning but without changing cam and injectors along with turbo what you have is what you got.

 

I drive a 99 n14+ with 1,200,000. It has run a lot of the miles at 1700rpm at 75 mph. It seems to get the same fuel mileage when it runs 65. 5.5 mpg.

 

Change your 3:08s with the guy that has the 4:11s in the 10 speed to 13 speed thread.

 

Wrong way that would raise his rpm even higher .. My guess is he's running a single overdrive on 22.5 tires or most likely a direct drive tranny on 24.5 tires .. Some 9 speeds were convertible to 13 speed I'm not sure if that gave you a higher overdrive or a underdrive on the splits