Not to be the barrer of bad tides an hope is not your case, But...My press-in Piston Pin came out an was riding the #4 cylinder wall ....Brand new build,I guess happened on the Dyno, I wasn't there (An was Pissed about) They gave me the car,It Ran ok ,the Oil pressure was a little bouncy,No smoke.. ,but every now an then ,Whoosh out the tail pipe white cloud,after 3 full tanks of gas cruising, clouds got worse an worst,Finally after searching everything you stated above,pulled the motor an found the Piston Pin damage...I wound up sleeving that cylinder but cracked it on this last explosion..(boost line slid off,30psi + from gt71),lol..8^(,Lesson # 452451 on my journey's , Go chrome molly sleeve if you have to if it's even repairable..If not it's another block
Good Luck