1998 Mazda B4000

Computer problem
1998 Mazda b4000 6 cyl Four Wheel Drive Manual

Hello, I am having a problem with my truck's engine not running right. It seems to be an ignition timing thing. It was coming in and out of it running fine one min. Then running rough the next. Then over nite it started making alot of valve noise and just not running right at all. The engine light never came on but I had it scanned anyway & there was no reading. I changed the crank pos. & Cam pos. Sensors, spark plugs & wires and had the coil tested and theres no change. I want to change the powertrain control module because from 95 to 98 they incorporated the ignition control module into it. Cant get it from the dealer for some reason but can get a remanu one online but they need to know if its for 8-57f calibration or 8-58t. Does anyone have any info or ideas on this. I'm just shooting in the dark. Thanks.