2001 Grand Cherokee

Need some advice about my 2001 Grand Cherokee limited with 83,000
miles on it.

I purchased it new, it was demo and took very good care of it changing
oil ever 3000 miles. Also kept up the maintenance according to the
manual.

The place (not the dealer!) where I get the fluids changed recommended
that I consider changing to synthetic oil . I was told there is a
special oil for engines over 75,000 miles.

Anyone have any advice/experience about using or changing to synthetic
oil?

I am also wondering about how long the 4.7l engine is generally good
for. In the past in this group I have heard that GCs tend to start
needing expensive work soon after 100,000 miles.

Any experiences with long engine life?

Thanks in advance.

Larry