I have the 3.5 in my Pacifica and it only requires regular unleaded.  I have
not had any problems running 87 octane.  I think the 3.5 is a bit more
modern design than the 3.3 also.  I say go for the increased power.

I can't speak to the 3.3, but have never heard anything bad about them.  I'm
driving a '94 LHS with the 3.5.  Bought the car new, and it has not quite
125K on it.  The only "break down" I can recall is when a thermostat failed,
causing it to overheat.  Granted, the car has been exceptionally maintained,
but I feel it is a good engine.  Quite peppy.  Has never run anything but
the lowest grade fuel, no problem.

I toyed with the idea of selling the car, but as I cleaned it up, I realized
it was too good a car to sell for no more than it would bring.  So, I had a
new timing belt installed, and a new water pump, since that had no impact on
labor cost.  The car owes me nothing, but continues to give.

They're both good engines, will last for years/miles.  The transmission is
the weak point.  Change the fluid every year and expect them to need
rebuilding every couple or three years or 120,000 miles.
Tim K.

The 3.3L or 3.5 in all pre 1999 models should be a good engine.

The 2.7L V6, available only after 1999, has been the target of consumer
group furor because of sludge buildup problems that have lead to many low
mileage failures whether they have been well maintained or not.  The 2.7L
was launched immediately after the Daimler merger.  Whether the severe cost
cutting enacted by Stuttgart had anything to do with this problem is hard to
tell.  Another common complaint on the 2.7L engine is that parts are
available for them only through the dealer   That may be simply because the
engine is too new for the aftermarket.

Knowing the pride Chrysler Corporation formerly took in it's engines, and
the dependability record that I have experienced with them, it is my
personal opinion that the 2.7L problems are directly related to the
"merger", or at least the internal engineering turmoil that resulted from
it.  Chrysler may have had other problems.  But their engines were
bulletproof.

I had a 3.3L in a 1993 Grand Caravan which I sold to a local fellow who
drives it back and forth to Florida often.  I sold it with 165K.  It now has
225K, and is still going strong with no oil use.  It did need one water pump
at about 140K.  That is it.

Robert
I have the 3.3 (Which is the prefered earlier engine because of t belt
issues and fuel rail issues with the 3.5) '94 Intrepid with a 150,000
on it and have only replaced spark plugs and wires. Today the car does
not use a drop of oil. I just had the trans resealed not rebuilt. I
also have a 2001 with the 2.7 with 30K plus. This engine has had a lot
of bad press because of premature failure, 30 to 60K. I use Mobil one
in it and fortunately have a 100K warranty. Time will tell.

Bill

I have a 3.5 NYer in the garage.  It's under re-construction.   (I'm slow on
the reconstruction).
Looks nice, but I don't need the hi-performance engine. The bits for the 3.5
engine are expensive.   I'd call to the local boneyards to see how many 3.3
and 3.5  engines are local to you.  I'd also call around and check on the
cost of an engine gasket set for each and maybe a set of pistons, or a crate
motor.  That would give you the no-sh.t numbers on what the differences are.

Mark (please enjoy my hindsight) Dunning

Our neighbor has an intrepid (3.3 engine)with 205,000 miles on it,
ever did anything to it other then replace the oxy sensor at 185k, and
the thing still runs and works great...wish my fords life expectancy
would be that good however I learned ford stands for "F-cked Over
Recycled Dodge". lol, <G>
Kent Fedor