Use the AC Iridium plugs about 7 ea. from Napa, or Autozone.

Any of the Iridium plugs should work well and give you another 80k miles
easily.  NGK, Denso or AC-Delco.  I would pick the lowest cost of those
three.   I would also stay away from Bosch Platinums as the tiny center
electrode is reported to give problems on some applications.

$2 plugs for your car are likely to be conventional and will work fine
for a shorter life span, probably in the 15k-30k range.  Platinums are
the next step up in service life and Iridiums are the longest lasting.

John

Definitely go with ACDelco plugs. I put NGK's in my old Bonnie's 3.8, and it
lost gas mileage. When I got my new Bonnie (1996) I used AcDelco and she
runs great, and gets around 28MPG on the highway, and that's with the
supercharged engine. I went with ACDelco wires as well.

You can't go wrong using what the factory used.

As long as it's running fine, I probably wouldn't mess with it. Plugs and
wires will usually give you some indication when they need to be changed.

Dave

Jim,

Don't believe everything the service manuals tell you.  I have a 2001
3.4 Impala, and my Helms book said the same thing.   Ridiculous.  You
have to be careful, but it's not really a problem - I've pulled and
reinstalled my plugs with no hassle.

Most of the work will be done by touch - but they should be reachable.
Be sure to use a real spark plug socket (with the rubber piece inside
to grip the plug.)  And of course, be careful and gentle upon
reinstallation to avoid stripping of threads - I always start mine by
hand, with just the socket and extension, before attaching the socket
wrench.

It's like on my Colorado p/u - to pull the front spark plug, they (the
factory manual) say you have to pull a zillion connectors, then
totally remove the wiring harness.   Uh, no.   Not necessary.    Or my
old BMW, where they said to change a heater core you had to chisel out
the steering column mounts.   I don't frigging think so (and didn't
need to.)

The guys who write these manuals badly need a reality check from their
mechanics.

- Larry A.

The real differences are located in your wallet.  Buying something other
than the GM recommended for your car isn't recommended.  New plugs will
last a hellofa long time nowadays since there is no more lead in gas.
Do you see yourself keeping the car past a 'hellofa' long time?  As to
jacking the engine:  I have a FWD Cadillac and I the 'procedure' is to
unbolt the rear of the engine and raise it to get to the rear bank of
plugs.  I was able to get my arm around the engine and with a
combination of tools R&R the rear bank plugs.  Start any plug by hand
only.....crossthreading is a no-no! Dab a bit of dielectric grease on
the threads/plug boot and get after it.

Heat breaks down plug wires over time.  If those are the originals
(80K), I'd change them.  Again, use recommended OEM plug wires.  Proper
maintenance saves money and extends lifespan.....in most
everything.....even in people!

Dave S(Texas)

If you've got the original plugs AC Delco plugs in there now, why not
get the same type / # that is already in the car.

I went 180,000 miles on the plug wires in my Bonneville before they were
changed at around 8 years old. I wanted to change them at 110,000 when
it was 5 years old but the Parts Dept at Pontiac said I didn't need them
yet.

Good Luck,

harryface
05 Park Avenue 45,044
91 Bonneville 307,187