1989 chevy 350 tbi transplant

[1project2many]

So we have
1) ignition timing that mysteriously "moved"
2) Fuel pulses, triggered by ignition mudule, don't seem to be happening when system voltage is low

Do we have spark while cranking? Maybe faulty module? It's common to see OE modules that won't produce spark and / or REF pulse during cranking but can be "tricked" into working for a short time by connecting light to B+ and touching + wire of pickup coil. Same thing if system voltage can be increased. Also have seen OE distributor pole piece ??lose?? magnetism. Seemed impossible, but no amount of new parts other than pole piece would create proper voltage at idle. And it happened more than once.

Also, silly question but did distributor get tightened properly when setting timing?

BTW, I've wanted for years and years to build a big Jimmy V6 with a good manifold and electronic timing and fuel control. Saw a guy outside of Casper, WY building a carby version using a homemade sheet metal intake, 455 Buick pistons, and heads from a 379 for a 72 1/2 ton 4X4. Too cool.