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I can understand not wanting to replace a $200 valve if you don't have to. But, I bet if you just yank it off every 50k miles and clean it the valve will last forever.

That statement, I believe, is spot on.  And, arguably the most important aspect and requirement to keep these engines alive and well for extended trouble-free mileages- PREVENTATIVE MAINTENANCE.

Since my first 1986 22RE Longbed pickup, and owning 14 Toyota vehicles, including a Supra, 4 trucks, and a Lexus IS250, I firmly believe that with proper and diligent preventative maintenance many failures and unexpected costs can be avoided.

Of course everyone has a different concept of cost of vehicle ownership, investment, and value.  During my 8 years of very active sandrailing, I was always amazed at the guys that would arrive at the dunes unprepared, consequently many of the guys would spend lots of time being nice and helping the guy fix something that should have been done before the planned 3-day week end get-together. As result, many of the members of group's play time on the dunes was drained by the guys who didn't do the prepping they should have.  Although it was pretty much a common occurence, I still think those regular perps were rather selfish and lazy.  Not wanting to be "that guy", I spent 1 or 2 weekends before the trip going over every square inch of my sandrail, refreshing the air filter, checking and changing oil, checking nuts & bolts, trickle charging the battery, checking lug nuts, tires for leaks. Then I made sure the same preventative maintenance was done to my tow truck and travel trailer.

At times I gave someone one of my spare parts, who "needed to borrow it" to fix a problem.  Sadly sometimes I never got  one back, and I would have to go buy another one replace my spare parts kit.

That's just my opinion - it may be worthless.

Gnarls.