I have a 94 Z that I want to change the plugs this weekend but not to sure what to use NGK TR55, AC Delco(stock), Autolite (APP106), or the high dollar iridum. I only have a few bolt on mostly stock. K&N flit kit, Flowmaster and air foil. I also have the SLP spark plug wrench hope it helps. Never change plug on an Fbody before.

 

I would just run the NGK TR55's with MSD 8.5 mm wires. If you haven't done them before, you will learn real quick that space is tight. You'll spend some time going from up top to underneath. Spark plug wrench might help, I've heard mini ratcheting wrenches help. I have done it with conventional tools before, found it helpful to put the socket (w/ extension if needed) on the plug and then slip the wrench in. Good luck.

 

y i hope you dont need to drive it to work on mnday! lol, just kidding but it might take all weekend.it rather take a firm shot in the jewels than change plugs in a 4th gen lt-1.
i have pretty big hands and didnt have to remove the alt. Your going to take more of them out from the bottom than the top,and i run tr55 in mine, but any of the ones you listed will work.if your not going to spray it ever, then id say go with iridium so you wont have to do it again for a while.this is a huge pain, but we have faith in you!
p.s. dont forget the antisieze on the threads berfore you install the new ones.

 

i just happend to think of a trick i used.slip a 1ft piece of vacume tube over the end of the plug (wire side)after breaking the plug loose.you can then spin the tube from a location that doesnt kill your hand.its like a flexable shaft/handle to thread or unthread your plugs with.

 

If you're only replacing the plugs, it won't take all weekend. Probably just a few hours, since it your first time. If you are doing wires too, it takes longer and you have to remove a few things (alt and ps pump).

How many miles are on the car? If they are the stockers, probably time for a good tune up. How is the car running? I'm a big advocate of "do it once, do it right".

If the car has a ton of miles and your budget permits...I would get a new AC Delco opti (preventative maintenance), the aforementioned plugs and wires, new water pump (if needed) and have piece of mind that you shouldn't have another problem for a long while. Throw in a new coil and have the ICM tested while you are at it.

 

Nothing wrong with the NGK TR-55s, they are a good plug, that is what I am running. Keep in mind though that it will require quicked interval changes as compared to the iridiums or platinums.

 

NGK TR55 IRADIUMS, .050 GAP. Pickup some shims and index the side electrode toward the intake valve. Use antisieze. Mark the tip of the plug with a little file so that you can feel where the tip of the side electrode is pointing and use shims to line the mark up with the intake valve.

Or not. JMHO

 

I've got over 177,XXX on my 94 Z all stock DD and have used AC, NGK & Bosch standard & +4s. Believe it or not, the car likes the cheap Standard Bosch platinum plugs the best. You'll do most of your work from under the car, so take your time & be patient. It also helps to have a friend with skinny arms for #8. I bought one of those "Sidewinder" ratchets orig. for the first time I changed plugs ~ what junk! I bought a 5/8 sparkplug socket w/ the nut end where the ratchet drive connects. I cut the socket down w/ chop saw (from the open end) such that it was just long enough to cover the spark plug (The spark plug connector ~ where it connects to the spark plug boot is actually up in the 3/8 drive opening) and use a ratcheting box wrench on it. Between that and the standard 3/8 drive spark plug socket with a flex head ratchet, you can get them all. I think SLP sells the cut down sockets if you do not want to make your own. Be patient & do not drop the plugs

 

Thanks for the info guys, I just order a double platnum autolite form oreilly auto and i already have the SLP plug wrench with the nut on the end. The car runs fine but I bought it used don't know when it was change last. I just know the opti and the water pump was brand new when i bought it a year ago. Its my toy and don't drive it much it only has 90000 mile and it in good shape.