Which wires in a masthead sloop rigged boat are under the highest
load?

I'm re-rigging my center cockpit 50' sloop (after 19 years) and need
to replace some turnbuckles. I'm thinking the new turnbuckles should
be on the wires with the highest loads - but don't know which ones
they are.

The rig is alum mast and boom, keel stepped. The boat is 38000 pounds
displacement. Mast is 52 ft above the deck and boom is 19 ft long.
Forestay (with Profurl), backstay (with insulators), 4 lowers (2 aft,
2 fwd), 2 intermediates, 2 uppers. The wire is all 3/8" stainless.
We never fly a spinaker and the max headsail is a 130% genoa.

Which wires are the highest loaded and where should the newest
turnbuckles go?