Semi-urgent engine problems pt2

[HaremStorm]

@evilunclegrimace I just had the an outlandish thought. When i did the timing job/reseal i had bought Horse-Shoe from my signature for the 350 that was in it and stripped both trucks of harness computer and motor then found a hairline crack by the back of my block on the 350 caused by god knows what.. So, I almost wonder if in my haste if I put the wrong computer back into Duckie even though i had marked which came from where. Would it have ever ran like that? would it show symptoms considering that the 4.3 is just a 350 missing the front 2 cyl? I don't know but i have the other computer and am tempted to swap them out. I wonder if it just took this long to show symptoms because my initial timing is set so damn high and it was just eating the extra fuel. It's always been rich even before it jumped timing.

 

[HaremStorm]

@Deancr11 @evilunclegrimace @Schurkey @618 Syndicate @Hipster
#solved.
So, as it happens obd1 data stream reveals all. I re-did the vac line for the egr, replaced map and a new 02 and now it purrs. Goes through its proper warmup and idles down right when I start to see the temp gauge. I still have stored codes for a VSS and my coolant temp on the intake even though that's brand new (sigh) gonna get a gm genuine coolant temp and try my luck with a smp VSS because it's not "necessary" and the genuine is $$$. Haven't done timing yet to dial it back some but I suspect (hope) that'll help with the little bit of fuel getting into the exhaust and backfiring.
Thank you all for your advice and time.

 

[618 Syndicate]

@Deancr11 @evilunclegrimace @Schurkey @618 Syndicate @Hipster
#solved.
So, as it happens obd1 data stream reveals all. I re-did the vac line for the egr, replaced map and a new 02 and now it purrs. Goes through its proper warmup and idles down right when I start to see the temp gauge. I still have stored codes for a VSS and my coolant temp on the intake even though that's brand new (sigh) gonna get a gm genuine coolant temp and try my luck with a smp VSS because it's not "necessary" and the genuine is $$$. Haven't done timing yet to dial it back some but I suspect (hope) that'll help with the little bit of fuel getting into the exhaust and backfiring.
Thank you all for your advice and time.

Good deal. Offer still stands.