Do yourself a favor. Have someone watch the tail lights, put your foot on the brake and ever so slightly wiggle the ts switch back and forth. My '64 loses it's left brake light if you don't keep the switch centered.
Matched sets are the way to go. If you trust that even the same Timken part# is the exact same angle as the old one made 20 years ago, let alone an offshore derivative... you should buy a lottery ticket!
Do not throw that new cone in on the old cup. Knock both cups out and install both new sets.
And hand pack the bearing.. not coat. FSM also tells you to fill the spindle cavity with grease, but I won't start that argument here! Lol