Timing off-- did I skip a tooth on the distributor?

[Dngrsone]

I rebuilt a 2.8L V6, 1988 vintage. I finally managed to get it running, but when I have the timing mark lined up right it runs like garbage. If I adjust the distributor cap until the engine runs more or less smoothly, then the timing is way off, like 120 degrees.

So, the question is, what did I screw up? I'm thinking that I managed to get the rotor out of phase. Any suggestions?

[MT-2500]

Get no one piston at TDC compression stroke.
Then point the dist rotor to no one plug wire.
Does the crank timing mark read/point to TDC cover mark when the piston is at TDC?

Some times the crank damper mark may be sliper/off or two sets of marks.

[Dngrsone]

Thanks, MT. Hopefully tomorrow I will be able to get in there and do TDC and check the rotor alignment. Someone also suggested I check the plug wires again and make sure they are in the correct firing sequence.