Over here in OZ CASTROL VMX-M 75W/85 is recommended for the manual transmission. Lots of kudos. The #2 synchro is un-necessarily complex and has a tendency to fail. The CASTROL VMX-M 75W/85 lube has helped lots of folks with notchy transmissions.

Check the hoses. I've blown them all over the years (blew another one today). Absolutely do not think you can make it a little further hot. Shut down immediately.

If it doesn't use oil, it will last a long time if you change the oil and filter religiously.

I have had several Gen1s and one Gen2. The Gen2 is larger, heavier, not as quick and not as much fun. I'm planning to sell it and look for another Gen1 SWB to replace it. I'll probably have to get a diesel since I don't believe the 3L was available in Japan or Australia in a SWB in '88 or '89. I'd prefer the 3L, but I'm limited to importing a auto manufactured in '88 or earlier here.