It seemed like I remember a place on the web that sold K code engines. Does anyone have a link?

 

That would be interesting. They rarely come up for sale, and command a good price.

Of course, except for the special heads, it's easy to duplicate the 289HP.

Air cleaner √
carb and spacer √
intake manifold
valve covers √
distributor
heads
exhaust manifolds √
camshaft √
pistons √
rods
"thin" timing set √
fan √
hatchet weight √
harmonic balancer √
"thick" main caps √

Everything I have checked is available new.
The intake is easy, that was the ordinary iron 4V manifold.
Exact heads are scarce and pricey, but other than the spring base retainer, were no different and no better than stock 2V. Have some plain heads upgraded.
Have standard rods fitted with 3/8" cap bolts.
Ford sold the distributor over the counter for about 20 years. eBay.