1. Radiator Flush

I'm attempting to do a radiator flush on my 94 cherokee, inline 6 4.0l.
It all seems pretty straight forward, but I can't shake the feeling that I've done something wrong or made it worse, perhaps. The radiator was full of dirty brown fluid. I've drained it all, sprayed it out with the hose, etc. When I went to refill it, I was only able to put about a gallon and a half of water into it to do the flush with. Couldn't get anymore in. What gives? Also, my radiator fan isn't blowing when I start the car. How long does it take for it to start blowing, or should it always be? Also, I've heard of burping the car but how I go about doing that is a little unclear. My heater core is bypassed so running my heater on max won't help me any. Do I just park on a hill and let it run for a bit?

2. Engine Swap

I've been looking at a nice 98 jeep with 285k miles. The asking price is $1500 but it's in immaculate shape other than the high mileage. I have a mechanic who will do an engine swap with a lower mileage cherokee for $500. Is that a good idea?

 

Everything else still has mega miles on it, you'll replace it all ($$$$$$) eventually.
Less expensive to buy one off the bat that isn't used up.

 

285k is not used up. Do you have any reason to suspect the engine has problems, other than the mileage? If not buy, it and drive it. Pick up an engine on the side and start the rebuild process, and worry about the swap when there's a reason to swap it. 285k on the odometer isn't a reason. I'm at 272k right now and my compression is 145 on all cylinders. I expect to pass 300k by a good margin. Many others have done so.

As for the flush, see my sig, #4.

 

this^^.

 

Just drive it.

 

Drive it, fix it up, tune it and see what happens.

 

If the cooling system was neglected chances are real good everything else was too, waste of dollars saving pennys.

 

The cooling flush is on his 94. The 285k is on the 98 he's looking at.

 

Needless to say I haven't even seen it but I'll say they are the same.