Go to a pinch a part and pull another set of towers from a L4 series engine. They should all be the same. Got to every car with a L series 4 banger and check them all for the best journals. Make sure you mark which ones are which i.e.: j1 j2 j3 j4. The set needs to come from the same car! They need to be kept in order. If the ones you find are a bit rough use grade 1500 wet and dry to polish them up a bit. Make sure you clean them with warm water and soap after the wet and dry. You want them as clean as possible (same with your whole engine). oil them up and off you go. The cam must spin free with no resistance in the journals. If cam doesn't un torque one journal and see if it was the journal that was binding. If it was use a hammer and metal dowel and knock either size and the top until it does not bind. Torque the journal bolts to 10-12 f. do no over tighten as you will strip the threads in the head. Then another can of worms will open. Finally check wipe pattern on your rocker and lash clearance. Front cam gear bolt should be at 100 f torque not what the service manual says, but I have seen they come loose. For more info on all of this on of this link. It will inform you about all this stuff.
http://www.datsport.com/Tek_Menu.html Good Luck.