My 1999 is at the crossroad of it's life, here are the issues:
steering rack leaking, vac pump leaking, oil pan weeping, rear diff leaking,water pump leaking, doors need replacing, rockers starting to go,and ball joints are knocking again,the newest symptom- slight miss at hiway speeds- thinking injectors
The cummins has been rock solid and i love this motor- just hit 210k miles- so it owes me nothing- just hard to make the change and give up on old reliable
i am thinking the repair bill would exceed the value of the truck and it may be time to move on- am i being reasonable?

 

It all depends if you could do 99.9% of repairs yourself,then it's worth it....But if you have to outsource the repairs....That's when it gets very costly...And your bank account will have a stroke...

 

I've been struggling with the same issue, because everything seems to go (or need replacing) around the same time. But then I fix it (need to in order to get decent cash from it anyhow right?) and all is good for a while. And it stinks shelling out for everything at once, but there's always a chance of having to do that with a new truck too, on top of having a monthly payment. So I'm with Dave on this one! Good luck.

 

If it was a 12 valve I'd fix it up, but since it isn't...

 

Here's the way I see it.......
To get a new truck that's equivalent to what I already have, I'd be spending $45-$50k. I can't justify that cost for something that's basically just personal transportation. If I had some sort of business that required a truck (or won the lottery!) then yes, I'd buy a new one. And to be perfectly honest, I really like not having a payment every month......

 

If it still runs and looks good I wold just fix the stuff one thing at a time and keep it.
Nothing you list is very serious, I would start with the suspension and go from there...