The engine had a small but persistent oil leak at the rear of the block. The head/intake manifold swap story revealed the origin: Both of the rear intake manifold bolts were missing. John Parsons is an engineer/hot rodder/upscale car builder who surmised that there may also be an internal pressure problem so he machined a rocker cover breather system and fabricated the corresponding overflow canister. The catch can end goes into the intake manifold, the breather side (that uses the original breather opening) on the tightly sealed Moroso sheetmetal rocker cover issues into K&N air intake tract. Primary ignition wires are solid-core 8mm Moroso. Parsons also fabbed a 1-inch spacer to move the alternator outward so that it would clear the end of the taller Moroso rocker cover).
Regarding a persistent engine misfire at proximately 4,500 rpm, he removed the early (and sometimes problematic) FAST eDIST module and installed a more modern FAST XIM box (thank you David Page) in its place. Then, all power and ground circuits were rewired. Parsons: “The actual problem with the original stuff was a badly frayed crank signal wire.” All of this conspired to make the engine cranking sequence way too long and the engine difficult (farting, backfiring, and the like) to start when cold. The new XIM module was the cure.
“The insulation was cracked and missing altogether in some spots. Worse, it was wound around the ground wire for the signal—a real mess. I redid the power and ground circuits so they come directly off the battery as recommended by FAST. Problem solved.”