Specs: Eb fairmont, 6into1 turbo manifold, 70mm turbo, bbm intake, 60lb injectors, el ecu with j3, 1x 044 pump inline being fed from stock intank pump, stock btr auto etc.
This is piston no.1 removed from the stock eb bottom end.

Suspected cause is a massive leanout due to dropping fuel pressure under boost. Fuel pressure dropped to 40psi under 20psi boost. I have another stock el motor just about ready to go in. Planned upgrades to prevent this happening again are surge tank with 2x 044s, plenum for better air distribution and care with tuning.
To be honest this motor would still be running if we stopped as soon as it was obvious it was too lean but it had been oiling up no5 plug for ages and i suspected a busted ring land. On inspection no5 piston was fine must have just been the old 236000km rings giving up slowly.