I have been recruited to reanimate an 8N tractor which survived a large fire event.
Most wiring was burned and there have been helpers installing things. I am now the sole repair man. 12v conversion done before fire.
I am an automobile mechanic.
Very little flathead experience.
How do I determine engine model and TDC.
Any help will be gratefully accepted. I am here to learn and go forward with guidance.

You may want to visit the Smith's old Ford Tractor website. Lots of great information there.

The serial number on the engine and casting dates in other locations will identify the year of manufacture. There were three different blocks produced from '48-52. The big difference between 8N engines is the location of the distributor. From '48 into 1950, the engines came with a front-mount distributor where the coil attaches to the top of the distributor. From mid-50 through '52, Ford went with a side-mount(aka angle-mount) distributor with a separate, round can type of coil.

Hit our Manuals library here for an owner's manual, dealer parts book, and FO-4 service manual. They should give you all the info you need to service your 8N.

Feel free to come back and ask all the questions you like.

Merry Christmas...........Ed