Hoyt,
Don't fret, you're doing fine.
Whether or not to run a filter has to do with the bypass filtration setups with the 1/4" lines that just dump what little goes through the filter back into the oil pan, not full flow filtration. Not taking advantage of full flow filtration when it's available doesn't make alot of sense to me...
The 261's with the factory full flow filtration setups are from 59-62 (and some '63 4X4's) and use 1/2" NPT fittings. They were always mounted to the intake manifold, just like the earlier bypass versions.
I see no real need in worrying about a fire, the factory did it without any problems, and all you're doing is basically replicating what the factory did, so don't sweat it. Just use some common sense and make sure all your connections are done right. Running hard line from the motor to a filter mounted somewhere other than on the motor would be an example of what not to do, as it wouldn't take into account chassis flexing.
Another thing to keep in mind is that even on full flow systems, there needs to be a way for the oil to bypass the filter when the oil pressure/volume becomes greater that what the filter can handle. Most engines have a bypass/relief valve somewhere in the block, but some have it in the filter itself. The factory had one in the filter head for the 59-62 261's. If you decide to run a spin-on type filter, and you do not have a way for the oil to bypass the filter, then you need to use a Ford filter which has the bypass built in. I don't know the filter number, but I know someone posted it on this site a couple months back. If any of this is unclear, let me know and I'll try to explain it better.
