In fact, it is very difficult to find excellent condition of
LM323K because there are a lot of pulled and/or counterfeits that cause
frustrate for us on S-100 group.
May I suggest you to redesign PCB to use LM323T, TO-220 package before order. Secondly, avoid TO-3 on future boards would be much easy for us.
For old boards that designed with TO-3 can convert to TO-220 by add low-profile heat sink, three 22AWG stranded wires, thermal compound and 3-pin connector and plug into the voltage regulator as much like Heathkit did in the past. This procedure will make easier to replace the voltage regulator quickly compared with soldered-in TO-3. Here is copied from Heathkit assembly manual for IM-2420, 512 MHz Frequency Counter to give you an idea.
Otherwise, if you have something better idea? Please post here..
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