Bought mine in 2007 w/ 35k on it then. Now at 57k miles
Time seems to run the clock on-
- -many of the soft (seals, etc) parts, especially those that get heated,
- -some electrical components, including some electronic parts such as the various filter capacitors (e.g., used in the Bose sound system), and the shellac insulation used on the ignition coils, and injectors windings. And, alcohol wrecks havoc (especially) with the stock 90-92 injectors.
- -Windshields have a reflective film laminated in the glass which tends to deteriorate from the edges inward (aka "delamination" or just "delam")
- -interior vinyl and carpet - especially susceptible to direct sun and/or high heat.
- -tires too become hard and brittle and unsafe after decades.
- -water pumps, for some reason too seem to "run the clock" and age whether or not the car was driven or not. (Mine died in the middle 40k miles)
Then there's wear items which should be replaced as needed, e.g., clutch components, wheel bearings (especially if tracked a lot), plugs, brake pads...stuff like that, i.e, normal wear and tear stuff.
These ^^ are the things my Z required since I bought it in 2007. You might notice, with exception of the injectors (alcohol issues), and maybe coils, the engine and drive train has been solid as are most Zs - you can ask around!
I wouldn't (and don't) give it a moment of thought to jump in and go for a long trip, e.g., cross country (I live in IL) to the Appalachian Mts to spend 3 days chasing around with other ZR-1 nuts before ending up in Bowling Green for festivities there.
And, I don't baby her either! It has now been 5 seasons ago now that I ported the LT5 and installed headers, etc. bringing it to 500+ hp with no issues or regrets! It is truly a "BEAST", and an adrenalin rush beit a short blast or long haul.
I've overhauled and hotrodded SBCs and Chevys since 1969, and I feel that all I came to know with regard to reliability, especially if driven hard - hard is pretty much confined to those motors. All that goes right out the window with the Z, especially at the 500+ hp level! The kind of punishment and revs I've subjected this motor to since i bought it probably would have destroyed (or worn extensively) a number of SBCs. These engines especially, along with the ZF etc (maintained properly) are bullet proof, including having bumped the rev limiter to 7600 rpm (to make room for the power it is now making past 7000).
Welcome to the "Brothers of the Beast"! Hope to hear about your purchase in the near future. I don't know what if anything we can do for the "permagrin" it will put on your face. (That's more or less indelible, I guess. Oh, well!)