Just bought my 94 GT!

I bought it from a guy I work with, and he told me it was ticking and he thought it was a collapsed lifter. Well he out in some Lucas additive and it stopped. He drove it for about a month with no problems. Now Ive had it for 3 days and the ticking is back.(After a burnout or two) It seems to be coming from the pass. side head. The car has a little over 200,000 miles on it. I have been thinking of rebuilding the motor, but after looking into it and seeing the the ECU doesnt like most high perf combos, im thinking of just buying a rebuilt or crate motor. Any advise on either what the ticking is and how to fix it or some recommendations on new motors. I was told if i get the 96-99 explorer 5.0 it will bolt right in and run on the same ecu but has the gt-40P heads? Any advise will be much appreciated thanks.

thanks guys. did an oil change today with 4 qts of 10w-30 and 1 qt of lucas additive. it stopped but i noticed a different sound. dound like a bearing wine. maybe coming from the pilot bearing in the tranny?? when i disengage the clutch(push it to the floor) i hear a roar? maybe the throwout bearing? any ideas?