My wife just did a HG on her '96 at just over 300K miles. Not a matter of neglect or abuse (as far as either of us could tell) - she's owned it since 119K miles and it's always had the proper Toyota red coolant in it (or the emerald Subaru coolant). It's just a matter of time for the older style composite gaskets when they sit between an iron block and an aluminum head (which move relative to each other as they warm up and cool down).

The stock OEM headgaskets have gone through 4 revisions (at least). Her '96 was built in Dec 95, so probably would have originally had the first revision. But what was in it when it failed was the second revision, possibly replaced in a recall for the early 96 production 5VZs(?).

Anyhow, on the plus side, at 304K miles, practically no ridge at the top of the piston ring travel, and crosshatching was still present on *most* of the bores, with just some small shiny areas on the 'rod throw' sides of the bores near the top. So... looking good for a long time to come. It was put together with the 4th revision MLS style HG's.

I'd say it probably worth having HG's put in.