i remain interested in an LJ78 but have not got the wife interested yet.
anyway, just an observation, but the 1fze gas motor in the 80 series is also prone to head gasket problems. there are several reasons and suggestions developed over time on the 80s forum that might provide insight or assistance here. fwiw, here are the 80 series "learnings"
1. the main one is that you won't have any problems so long as your coolant system is running perfectly. in the chicken and egg debate, I think the conclusion i have have reached from post mortems I have followed is that for 80s overheating blows h/g's rather than the overheating being a symptom of a blown h/g. also, it is often slight overheating fatigue rather than one single big overheat.
2. toyota red coolant does not mix with other green coolants and forms a gooey mess blocking coolant passages. you must do a complete flush of any new 1fz 80 including heater core you buy unless you know it has always had one or the other type of coolant. maybe that should be step one with a prado as well.
3 you cannot trust toyota factory temp gauges to tell you you are in trouble until it is too late. 80s have "numb" factory temp gauges (it says so in kanji on the back). on a 93-94 there is no gauge response from 140 to 215 degrees, and you are at 225 by the time you get to 3/4 hot on the gauge. on a 95-97 the gauge is numb from 170 to 230. It is at 260 when it hits the red line. you need an aftermarket temp gauge to spot problems so Crushers pyrometer idea seems to me to be an excellent idea.
3. blocked rads are fairly common in 80s not only from coolant sludge but a mysterious grey grit that could be some kind of crystalized residue from coolant or some kind of chemical reaction to metals in the coolant system. I get some in the overflow even if I clean out the overflow. there has been speculation that toyota red causes it.
4. the original fan clutch on 80s can head south leaving you with limited or no function. toyota has changed the fan clutch part to a more robust aisin model. no idea if the 2LT has a fan clutch, but it is possible.
5. no idea if it will work in a diesel but slee offroad swears by a "bubbles" in the rad overflow tank test for early signs of h/g failure on a 1fz. pop the lid, keep the line immersed and watch for bubbles. time and again others have seen it even when leakdown tests etc.. have been inconclusive. i can verify mine does not blow bubbles...
6. a $20 mail in engine oil sample analysis from
www.blackstone-labs.com will tell you if there is any anti-freeze in your engine oil along with a bunch of other interesting details. again, maybe an early step with a new to you 2LT prado.
7. although it seems a bit extreme, a couple of people have done 1fz h/g replacements as PM. there is a part # changeover and the replacement h/g is noticably more robust and the design near the #6 cylinder that typically blows has changed. Again, it might be worth checking whether there has been a pn# changeover on the 2LT head gasket.
still thinking about a 2LT
) so who knows
