Spark Plug replacement - anything else while I'm there ?
 

I'm planning on replacing the spark plugs, wires, distributors, rotors on my 1993 LS400 (85,000 miles). Anything else I should replace while doing this. Are the spark plug tube gaskets replaceable etc ??

(I've alreay replaced air filter, PCV, etc.)

How about your thermostat and antifreeze since you have to drain some antifreeze before removing the reservoir tank inlet hose from the #2 covers? I removed the upper hose for easier access. This was on my 95 LS400 which I suspect has a similar engine set up as your SC400.