engine problems!

I just replaced the H/G in my 4.0 cherokee and now the oil presure is high, the engine is running rough and its ticking. Is there any way to figure out what I did rong and how to fix it?

How long didi the engine set with the head off. If for a couple days your ticking is probably due to a lifter that isn't fully pumped up with oil. It "could" cause ruff idle but should clear up in less than 5 minutes. How high is the pressure? 50-60 psi(cold) on a high milage engine is good. WHen you installed the gasket, you got the right side up and installed correctly? If I remember right, the 4.0 does not have dowel pins to aid in aligning the gasket. Also are you sure that you torqued the head down correctly?
WHen I did mine ( 89 4.0) the hardest thing was getting that bolt at the rear torqued, (had to adjust the sheet metal a bit) I used the Heavy duty H/G from NApa, also went and lapped the valves and installed new valve seals.
Running rough could be from a vacuum leak at the intake, be sure that your intake and exhaust bolts are torqued and the washers are contacting both surfaces evenly. I will assume that you used new gaskets. Outside of that, there is really no relation between the H/G r&r, and oil pressure, all the oil pressure is maintained in the bottom end, except for the pushrods. Did you double check them to be sure that they are clear? To verify that your getting oil threw them Remove the valve cover and crank the engine over (igniton disabled) you should see oil oozing from the rockers( those too need to be torqued and seated correctly on the pushrods, and the towers that they bolt to) Hope this helps some.