Hey Ferm, or anyone that knows diesels

[spareparts]

Ferm or any one with 7.3 knowledge. I've got a 1997 F350 7.3/5 speed 2wd. Going thru a few issues with it, trying to get decent milage out of it. I found an exhaust leak around the turbine housing. Rebuild looks pretty staright forward on the turbo. Whers the best place to get parts. I've got the parts in my cart at Rock Auto, just don't know the brand. Any place better?
BTW, I've already put Diamond Eye 4" exhaust, and the air filter upgrade. It went from 10 mpg to 14 mpg unloaded, highway speed. Still looking for a little more out of it. Seems they don't like the rpms of running 70 +. I have 235/85 16 all the way around, wish I had gone taller. Tach reads around 2500 at 70 mph. 65 MPH on I95 sucks. Thinking about making it 4wd, found a 5 speed/271(?) transmission/transfer case. Need a dually width drivers side drop D60 for the front. I'd rather have the 6 peed if I can find one. .72 OD vs .76. Not much, but combine it with 33's and should put me right where I need it to be

[THEFERMANATOR]

Thats alot of RPM's for that engine to be spinning. I would think f all was well, it should still get mid to high teens for milage. The 7.3L is a bit of a dog, but was known to pull alot of weight(slowly, but would maintain speed on some steep inclines), and get good milage. I believe many upgrade the tuning and go to a different stryle of injector to get a good boost in power and economy. If your looking for to much out of it, you're going to need to intercool it. Theres no intercooler on that engine from the factory, and it really hurts them. Also make sure your high pressure oil crossover is good, and consider flushing out the HPOP reservoir. Theres a guy on youtube with ALOT of GOOD powerstroke videos that lists off alot of things to check and do to them. And give DPTUNER a call for tuning as he is considered about the best for 7.3's.

[spareparts]

from what Ive read on these models, an intercooler doesnt help much umless you go to a bigger turbo, and the bigger turbo doesnt help unless you get bigger injectors. Add it all up and I could buy a better truck for the money. Right now I'm just trying to get de ent power by bringing it up to speed and try to get a little better mpg out of it. 4wd drive conversion would just be for the fun of it. DP tuners seems to be the go to on software. Now, if I could only get the rpms down a bit. F250s run 355 gears and regulary get 17+ mpg. I'll see what kind of front axle I run across and go from there. The 6 speed swap and 33" tire would put me where I want to be, keeping the 5 speed and 35's would work as well

[THEFERMANATOR]

You should be turning around 2300 at 70 according to the gear ratio calculator. Going to the 6 speed would only drop you 130 RPM's at 70 MPH.

[spareparts]

I ran those numbers myself this morning, I guess the tach is off and my tires are short, still drinks fuel and sounds like its screaming at 70 mph. I couldn't get torque on my phone to work on the truck, speaking of which, you know any software(free) that may work, I do have a patch cable to plug into the OBD port from my computer, I'd gladly take that 130 rpm. The numbers work if you plug in 456 gears, I need to check the tag on the rear end, the door sticker says 410, but something isn't adding up right

[oteps]

I would spin the rear and check the gearing. Maybe someone changed it. did u replace the down pipe when u did the exhaust? Its the one between the firewall and engine.
U may be better off buying a rusted out 4x4 truck with the gears ratio you want to use for parts. we have a lot of them up here.
I have a 99 f350 7.3. I was getting around 18 mpg. haven't checked it since stage 1 injectors and chip.