The usual 300k+ mile 4th gens you see are usually stock, does this mean with the basic mods suspension lift, bigger tires etc would affect longevity with good maintenance. Trying to dispel this or if guys with mods are at 300k+

Doesn't always mean that the mods reduced the life. Folks that make the mods may also thrash the vehicles, and that is what reduced the life.

I'm at 220k with a heavily modified rock crawler. It gets beat on. 35s, air locked 4.88 diffs, 3/8 steel full skid plates, shorty headers, big steel bumpers, dom sliders, rcv cv axles, diamond plate driver side cargo window, dual battery, high output alternator, pedal commander thingy... I wouldn't say I thrash it, but a reasonable person might say that I do. I did once send the front diff into the oil pan.

I fully expect to reach 1 million miles with this engine.

The weaker tundra 4.7s have done it. I would think hotshotting is harder than driving 100 miles to do a 30 mile rock trail and driving back.

I swap all my tranny fluid every year, all 12 quarts.
I check rear diff and transfer case fluid regularly. I pop one of my axles out often enough I don't worry much about the front diff fluid. Usually looks clean as it runs down the pavement

Depends on many things
- For the v8s and the V6s that are late 05 or newer you have to look at whats likely to fail
- For those of us inthe rust belt - the frame is likely to go before anything else
- 03-05 4th gens have slight increased risk of head gasket failure and transmission failure (likely cooling/ temp gauge issues among others)
- for everything else, as long as you take care of it, it will go as long as you want it to. I think that just regular maintenance and expected parts going on it start to outweight the value of the vehicle at some point. (Ie if youve got a 300 K 06 with some dings it may only be worth 5k and so if you have something that unexpectedly gives out do you want to pay 1200 for it
- nothing other than is expected to fail as long as you take care of it

There's a vehicle trifecta you'll see mentioned on occasion... Cost, Reliability, Capability. You can pick two. You add 35s to your 4runner, you're going to need to buy better brakes or plan to replace them more often. Really, I'm pretty sure rust will kill my 4runner before anything else and I live in Texas.

Great to hear, let the light mods begin, going. For the minimalist look.