Definately sounds like busted timing gears. If the B18/20 has a weak spot, that would be it - the fiber timing gear. Some people ave them last 250K miles (how many miles does Irv Gordon have on his?), some people chew through them in 25k miles.

The distributor drive gear does two things. First, obviously, is turn the distributor with the top side. The second less obvious thing is to turn the oil pump with the bottom end. This interface consists of a slot on the oil pump and a spade (like a screwdriver) on the bottom of the drive gear. When you pull the gear up it turns, when you push it back down if the motor has turned at all then the slot on the oil pump and the tab on the drive gear won't match, and it won't go down that last 1/3rd inch. I've always found it to be a bit of a struggle to get those two to match up. Not to mention that you want to get the gear in the proper alignment at #1 TDC as well, so you don't have to do anything funny with the spark plug wires. Which isn't always easy, as picking the right tooth to start out on is hard to do when it rotates on the way down, and even more when it finally engages with the oil pump. I typically end up hassling with it repeatedly before getting it right. Last spring's bottom end rebuild included a HD IPD oil pump which makes this even harder, because you really have to force the drive gear into the oil pump slot when that reinforcing ring is there - even after gently dremeling the drive tab a little.

Changing timing gears isn't a huge task - take the radiator out for more room at the front of the engine, you'll waste more time and expend more curse words trying to work with the radiator in place. Take off the grille too and you'll even be able to see what you are doing more clearly. Hopefully there is enough of the fiber gear left to pull it off with a gear puller, or you have a problem on your hands.
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I'm JohnMc, and I approved this message.