Well, it's been three months to the day that I tore into my Suburban thinking I had a leaking freeze plug. I know I haven't been very diligent about posting in my progress, but with work and cold/rainy weather it's been a slow progress. As of today the engine is 100% back together. I've done the following:
1. Replaced the lower manifold gasket. This turned out to be the cause of the leaking coolant. It had been done before, and it was a mess. No leaks now.
2. Installed the new fangled Spider MPFI device. Works.
3. Replaced the power steering pump and steering box.
4. Replaced the distributor, wires, and plugs.
5. Replaced the serpentine belt and both idle pulleys.
6. Pulled the dash and HVAC box and replaced the blend door assembly and all three actuators.
I had a heck of a time when I first started it up. It was hydrolocking and wouldn't start. I suspected it was a timing issue and I was right. I had put the replacement distributor back in the same orientation as the original one, and it was wrong. Thanks to a very informative YouTube video I was able to get it in correctly. The truck runs smoothly, but I have two problems:
1. Despite having a CMP Offset of 1.38, it's still throwing a Camshaft position sensor code. I used the Torque app to set the CMP Offset and was sure to take the reading at over 1000RPMs.
2. Even after performing an actuator calibration (disconnecting the battery, reconnecting it, turning the key to "on" and waiting for at least a minute) the temperature and blend door actuators do nothing. It's stuck blowing cold are out at floor vent. The controller connectors are seated properly. The fan dial works.
If anyone has any ideas on these two issues, please reply. I greatly appreciate any and all assistance.