I have a 2001 at 350 with a v10 I do not know the actual mileage the truck has been pieced together a slightly lol
Cylinders 3 and 4 are missfiring with no compression I was told to bring in cylinder 3 to top dead center and push air down to the cylinder and it came out my intake But not that strong Nothing came through the crankcase If there was it was so slight that I did not notice The truck still runs but you can definitely hear the misfire through the exhaust if you put a bill at the tailpipe it will suck it in and push it out The truck really does not burn any oil eithe rMaybe a 2 or 3 courts every 3000 milesThe truck still has plenty of power to pull a trailer just trying to figure out what I'm dealing with

 

You say no compression? As in below normal compression ranges? Or at zero? If there is no compression in these cylinders, then I'd assume the rings/seals are bad.

 

 

If you're burning that much oil you've got a real problem.

I think with those conditions, I'd just start saving for a replacement engine.

 

I just figured it wasn't that much because I've had a few V 10s that drank oil But they ran great this one I've probably put 400 000 miles on myself I'm guessing the truck to be around 6 or 700000 And it's so pulls 15 and 20K trailers But I will admit it does not like hills at all

 

If you have two adjacent cylinders with no compression then it could be a head gasket blown between cylinders. You say you put #3 at tdc and the air went out the intake? Did you have it at tdc or the piston at top of cylinder on the exhaust stroke?

Pull 3 and 4 spark plugs. Make sure they are at tdc with both valves closed and repeat the air test. If air comes out the other cylinder you most likely have a blown gasket. If you have a suck and pressure at tailpipe it could be a exhaust valve but you can't tell for sure until you eliminate the head gasket.