I got my boat out for the first time this year today, been towing it around town getting stuff fixed up on it from the off-season and it felt fine towing around.

Launching the boat today was uneventful (except for the ramp being muddy and covered in loose gravel making me spin all 4's), but pulling the boat up a fairly steep grade hill from the launch felt like crap.
The grade is pretty high, not sure exactly but it seems like 35 degrees, pretty damn steep.

Its an auto-tranny, put it into second while going up, RPMs wouldnt climb above 2,200, turbo was going good, but it just couldn't increase RPMs. It started slowing down near the top, didn't quite bog down, RPMs were still above 2k, but it felt like it lost the battle and was going to give up speed.

I've never felt that from this truck so far (only owned it for 6 months), but the motor does have 300k on it.
My old Chevy 1500 with a 350 in it would tackle that hill with the same boat without breaking a sweat (albeit at 3,800 RPM, not the 2,000 rpm the 7.3 seems to like)

Boat and trailer probably only weigh 2,500 wet (fueled up with toys in it).
Just felt the truck was going to slog down, and have to downshift to first just to crest the hill

Being relatively new to the 7.3, I don't know what to expect, but I'd hope it would breeze through steep grades without a sweat, what are people's experience with steep grades? Slow and steady, or able to blast up them not even thinking?

 

Dont undersell the 7.3. I dont like the 4 speed that it's paired with because it often makes me feel like I need another gear. Because of the narrow RPM band theres not much you can do but putt in a situation like that. You dont want to floor it for fear of losing traction. I would say do a normal tune up and if you find nothing go for a drive and see how it feels.

Check for boost leaks, fuel pressure, etc.

At 300k miles I would expect the injectors to be tired, but it shouldnt leave you wanting power in that situation. My guess is that everything is okay and you were simply caught in a low RPM situation.

There are many times (you will come to learn) where the truck is in the low RPMs and EGTs skyrocket as you accelerate, simply because there is not a gear suitable for your speed to get you to accelerate better. I find this at freeway speeds. If I am cruising at 65MPH and go to pass.

I wouldnt worry too much, spend time under the hood and driving your truck to get used to it.

 

Why use 2nd? Why not low or just Drive? From a stop in 2nd, I don't think I would pull any hill very well, since it's in 2nd. On boat ramps since I have a 4wd, I generally put it in low range, I don't lock the hubs, just low range.

 

When you put the 4r100 in 2nd, it is just in 2nd, it won't go down to 1st, it's designed that way to reduce rear wheel torque for low traction situations. So the transmission is going to slip a lot more from a stop in the boat ramp situation. Next time try just putting it in drive and let the PCM decide what gear you should be in.

Also, make sure the tin nut on the back of the IPR is on and tight.