The block should be fine, the head should be checked for true and pressure tested before reinstalling it. What HG did you use? Might want to opt for a Toyota one over a parts house brand, you can get them for about $40 through any of the online Toyota dealers.

I would go through the cooling system while you have it apart, check/replace any of the rad hoses if soft/easy to squeeze, replace the thermostat(only use a Toyota one), depending on age have the rad rodded out if you can find a shop that still does it or replace it.

At 400k, it may be due for a rebuild, though as long as there wasn't any "knock" on start-up or loud clackety-clack noise(it is louder than the Toyota valve tap) while running, it should be good to go until you decide to rebuild it.