After Market Spark Plugs

[RareGMFan]

Ok, I think I just found out that my plug wires are the originals from '90  :shock:  (they're still numbered 1-6 on the wires), so I would like to replace the plugs and wires this weekend.  I have already selected the Magnecor KV-85 #6540 for the wires.  As for the plugs, I'm still not sure yet.  I know certain types don't work too well on the turbo motor.  I was wondering what anyone thought of the NGK V-Spec TR5 series.  They're reasonably priced, but are they any kind of improvement over the stock Delcos?  Will they work ok?  Any other suggestions besides forking over $40+ for Irediums (which is not out of the question, yet  :wink: )?

[4PASNU]

A few months back I was looking into the spark plug thing as well so I contacted NGK directly.  I asked them what plug they recommended if I wanted to go one heat range colder.  They told me to use a TR6 plug stock number 4177.  I'm lazy and still haven't done it yet but I thought I'd give you this info just in case you might want to use it.

[RareGMFan]

That's great info!  They're not platinum or anything, are they?  If not, I'll look into getting them immediately.

[4PASNU]

http://www.ngksparkplugs.com/products/cars_trucks_suvs/vpower.asp?nav=11000&country=US

You can read all about them at this link.  Also click on "Closer Look" and it gives you even more info.

[RareGMFan]

Yeah, I knew that much.  I was just wondering what the difference between the TR5 and TR6 V-Specs are.  I'm also still debating going for broke and getting Iridiums.

[brian89gp]

the TR6's are 1 heat range colder then the TR5's.  NGK specifies 100-150hp per heat range step.

Stock 3.4 DOHC are R42LTSM AC delco's and TR5 NGK plugs.  No idea what the TGP uses.