Just a quick back story and what led up to the now no-start condition. I have a 2003 "3.8" that I guess you could say is heavily modded. Right before covid hit, I spun a crank bearing and had to get the engine tore apart. I had the bottom end rebuilt with a bore and stroke. After getting it back from the machine shop, I drove it fine for years. Last summer I had a lifter fail and found out later that I also had floated a valve, which damaged the valve and jumped timing. Over the last year I diagnosed and completely rebuilt the top end. I got new heads with valves and all already installed. I port matched the heads, installed with ARP studs, new 1.73 Scorpion roller rockers, new cam, and I replaced the timing chain, cam gear and timing gear. All new from Ford. I have also replaced about every sensor on the engine. Everything was running great and I performed the proper break-in. After hitting almost 2k miles while I was driving home from work on the interstate, going 70mph at 2.5k rpm, there was some loud rattle at the valve train and my car billowed what looked to be white smoke. It was hard to tell because it was at night. I managed to limp it to the exit and it died at the intersection. After a few tries, it started again but rough, then normal, peppy for a second before dying again as I drifted into a parking lot. I had 0 leaks under the car, no codes except for misfire as I tried cranking again, all temps and gauges were reading normal, I have oil pressure, and the oil is clean. It will turn over, but won't start. As it tried to start, everything sounds normal, as in no banging around, and it eventually loads up on gas and pops. Before I have to completely tear into the motor again, I was wondering if anyone had any insight for me? I've spend thousands and a lot of time trying to make sure the engine was "new" and back together perfect.