Ok, the ranger cam sychronizer appears to work but now that it seems the explorer engine had issues before I swapped it. Changed the plugs & the old ones were all oil fouled on the drivers side & one was crusted over. New plugs on drivers side all blackened with only minutes of run time, passenger side is still spotless.
When running it backfires out the the exhaust till you give it throttle, then the backfire pretty much goes away & it begins to ping some instead.
Has new plugs, wires, exhaust manifold gaskets, intake plenum rings & the injectors have been cleaned/swapped around with the same result. Also tried different 02 sensors with no change & it's not throwing any codes. I've also checked the vauum lines & replaced what was leaking.
As best I can tell it's running rich on the drivers side but I'm fairly certain nothing outside the engine is causing it, could a bad intake manifold gasket do it or maybe something in the valvetrain? There's no tapping or clicking noise as it runs.