if your not having a problem with your car, then there's no reason to replace the sparkplugs in your monte,GM states 10 years or 100,000 miles. The stock plugs are very good plugs,because they are a pain in the *** to change,that's one reason why GM uses better sparkplugs.Hell, i this replace my wife's plugs in her 1990 buick lasaber 3.8, stock AC delco 15 years & 85,000 old. The reason i change them out was her car was very, very hard to start last winter,now it runs like a top.

 

the reson why i changed my plugs at a early interval because the shopes i worked at. took a wratchet and socet to the plugs on a gm car that just turned 100k on it and we couldent get them out and had to take the heads to a machine shop to take them out. we ate majority of the caughst but we had other things done to the heads but the spark plugs were pretty sezed in. we recomend to our custimers do them about 50k to 85 depending hoe they drive and driving conditions. we explane why there is a good thing to do it at 50k-85 do to seizing of the plugs to the heads. do to weather strieght down driver error as in over heating as in broken hose. what i mean is going over like 85k is askin a meachine shop to remove the plugs so becarefull when doing a tune up. dont go over what makes a person feel good on doing it if it is at 35-85k if going over that my opinion and experence is asking for unnessecery caughst to remove the spark plugs from the heads

 

hay bob please dont get mad its just aa opinion and experence on my end so please dont get mad

 

Haynes manual for the Monte Calo/ Impala,,cost me 25$,,,saved me a lot on services.
Duderino

 

Just had a buddy do my plugs for me, my car is close to 101500mi on it and they have never been changed... I bought i believe autolight iridium plugs for about 45 bux for 6, and a little bit of spark plug grease. He did have to take the coil pack out in order to reach the back 3 plugs and this was a bit of a pain. We didnt take out the alternator although the plug closest to the alternator was a PAIN!!! They needed to be changed really badly, my friend told me the plugs had all sorts of problems. I dont know much about spark plugs but i can tell you they looked like CRAP!!!!!! Any way after the change the ride seems so much smoother.

Im looking into spark plug wires and i have no idea what would be best for my monte. Any suggestions of brand or size? Again i know nothing about plugs and wires so any info helps