First 4Runner questions

I previously owned an 86 Mazda B2000 and a '97 Ranger. I wasn't interested in vehicle mechanics when they when died but to shorten it up, I've replaced most of a '99 Honda Accord 2.3 manual engine over the past few years.

This is a '95 3.0, no extra descriptors like limited or ex and the like from what I can tell, V6. The only newly replaced part in this engine is a brand new brake booster, the last large part replacement was the timing belts at 124k, currently 214k. Knock sensor code and a bad oil leak from the top of the driver's side cylinder head is what I'm starting with, truck still drives though. While I'm in there replacing those parts and all the belts, what else should I keep an eye out for in general? I don't know about any of the most common problems with this truck if there is any (for example, Honda EVAP canisters or Ford transmission kind of common problems). Plan to hit the oil leak, knock sensor and belts all in one go, info on other problem parts on the way in and out of that path would be greatly appreciated. Mostly since it's the first Toyota I've played with...

 

I would just do a 3.4 swap and call it a day. 3.0 is a headache, head gasket problems, knock sensor....etc.....

 

I actually like head gasket jobs but I'm weird like that, I did the gasket once on my Honda then did the water pump months later while um... Inebriated XD. Bent open 6 valves so I ended up replacing the entire head and gasket again.

On this 4Runner though I did change the oil, plugs, air filter and scrubbed the gunk off most of the block today. Made a snowman out of the sludge and wire brush scrubbed the area around what I assume is the head gasket driver's side (passenger side is completely free of oil already). There's fresh drippy drips from that area after a trip to the lake, thankfully only a line of oil from up top is on the transmission area. Pretty sure every vehicle has a rear main and that's the only job I've come across that I despise. Ordered and waiting now... On to the sound system .