Ignition problems with 75 Maverick

75 Maverick with a 302. After valve job and timing chain replacement, I cannot get any spark at the distributor.

Have replaced the 'computer', the pickup coil in the distributor, and the coil. I have current to the leads at the distributor, but no spark coming out of the distributor.

If I accidentally got the timing chain/gear assembly off by one tooth, would that cause a complete loss of spark at the distributor?

Help please!?

Thanks....

notbarry