Hi Bob,
By any chance, do you own that funny car?

Your TVF looks to be about 8 miles south of me and w/in 1 or 2 degrees in both directions.
3/16" cable may be a bit overkill, but if you have it readily available, why not?
I always recommend trying to hit a rafter w/ at least one of the tripod feet and drill a pilot because those lag bolts can snap.
Underneath the remaining feet, you could also run lengths of 2X4 to act as load spreaders. Again, use pilot holes.