When the engine turned over heard the poof. What does that tell me? It sounded almost like a hose popped free. Then I noticed a small amount of smoke and by the time I opened the hood, couldn't trace its source.
I tested the msd wiring. In trunk, 12v between battery and before fusible link; 12v between battery and after fusible link. At msd box, 12v between red + and black -. 12v between Msd red and intake ground. Guess my msd didn't fry?
Would switching plug wires 4 and 6 at the heads cause smoke? Possibly a loose plug wire not snapped onto the spark plug?
Something popped like a fuse or a relay. Switching the plug wires would not have the effect you describe. Why was the hood down? Where you are in the process, the hood should be open and a fire extinguisher handy.
It sounds like you need to start tracing and checking all of the connections to determine what is getting power and what isn't. This is a fairly simple situation in terms of concept, however it can be frustrating at times figuring it out. There are a lot of work arounds to get power to where it needs to be but you need to start with the basics. Make sure that your distributor cap is wired correctly; understand the direction the rotor turns when it cranks over and then wire it accordingly (seems simple but I am quite sure many on here have wired a cap backwards at least once, I know I have). Also, check any/all ballast resistors in the system, when they blow they can make a "pop" and produce some smoke (other times they just stop working). Check the coil to ensure it is working; swap it out if unsure. Check all of your fuses to include the fusable link.
Generally, you need to be methodical about this and do not just look for the obvious, run each system down one at a time. Plugs and plug wires are usually not the problem for not starting (running rough for sure, but not starting).
Stay with it, trace everything, test your wires and eventually you will find it.