u/Numerous_Map_392

So 6 out of the 8 exaust valves were .004 over and 2 were .006 under. Ive been going crazy trying to figure out why this car is misfirig after rebuilding the motor and I think this is the problem seeing the ignition and fuel systems all checked out as functional. Timing is spot on and compression is consistent across all 4 at 150. Where can I order new tappets in the right thickness? I am looking online but don't see anyone selling tappets with different thicknesses. Any help would be appreciated.

So i got my ST back running after having a cracked head on the original top end. Got a rebuilt head that had all new components, did a new head gasket, timing chain, water pump basically the whole front cover and everything under it is brand new oem.ford parts.

Im getting a misfire over 5k at WOT. It throws a P0300 and sometimes p0301,302 along with it but only if you best on it. I have changed the plugs, tried different gaps, changed coils, did a new purge valve and a new front 02 sensor all to no avail. Compression was 150.150.150 150. Nothing is helping. What else can I do besides pay someone to look at it. P.S i.am a mechanic just not a master tech by no means. Any suggestions will help a lot.