GTerGone

Oh...and I turned the engine over a few times without the plugs in to try to remove any PB that could be in the cylinders so it wouldn't hydro lock the engine.

V8StickConv

Thanks BL817 and Rider for the info on the Lisle 65600 doing the job. I had read somewhere that you could replace the 2 piece set up with conventional spark plugs. Is that what you did? If so, what spark plug number did you use?

My 4.6 is an OK performer up to about 4000 rpm. Then it takes off like a bat out of hell. I 'm trying to achieve better low end performance. Ben

bl817

you can try the one piece champions. I also have an early 05' (built in late 04) I changed the plugs out at 35000. I did all the reading and got the Lisle 65600 tool. I ran a can of chemtool b12 or something like that thru a tank of gas first to help remove some carbon buildup. cracked and soaked etc, they all came out with no problems. I then replaced the oem plugs with E3 plugs and got multiple misfire codes. took em out and tried the autolite HT1 plugs, more misfire codes. put back in the original plugs and codes went away. all while replacing and running back to parts store PITA. anyway, its up to you of course what plugs you use, but I would recommend the oem motorcraft sp-514 with nickel anti-seize on the snouts only, not ground strap. I found a set on CL for 50$ and gonna change them out soon. good luck

V8StickConv

Thanks, BL. It's always better to draw on someone else's experience than to reinvent the wheel. Motorcraft SP-514 is one expensive plug. Cheapest set I've seen is $80. On the other hand, what's $80 compared to problems from a low quality tune up? Ben

Rider4life76

Hello, sorry took me long time to reply, I bought the 1 piece MSD spark plugs and they are working very good, on the expensive side but i wanted the best for my 08 gt mustang. My mustang uses black coil boots so i got the P/N: 37164, plug type 3IR6, gap at .035

Rubicon

I just replaced my plugs on my 06 GT with 40k miles and did all the "tricks off the internet" everything was going smooth until the last plug. I did the loosen a 1/4 turn let all the plug soak but on the last one I was so excited how easy the rest came out I didn't do the tighten then loosen 1/2 turn and tighten and loosen again I just started loosening it because there was no screeching like the others. Yup got in a hurry and broke it. I borrowed the tool from the local shop to remove mine, it was a Matco. Turns out when I was reading the directions it was actually the Lisle tool branded for Matco. Pulled that plug in a heartbeat no problems.

One thing I would mention, I see the lisle tool in two versions, one with a blue guide and one with a silver guide. The blue is the older version and can be bought cheaper. I don't know what the difference is but the one I used was the silver. FWIW.

V8StickConv

Hi Rider & Rubicon: I bought the Lisle 65600 with the silver guide. I didn't think the price was too bad at $57.79 including ship. True Blue was the ebay seller.

The 37164 3IR6 MSD spark plugs are running $120 for a set of 8 wherever I look. Ouch! I once paid $60 for a set of spark plugs and thought that was a lot. Do you think they're worth the money over the Motorcraft SP-514? thanks, Ben

Rubicon

I replaced with the Motorcraft. All I have for mods is a Ford Racing CAI and the tune so I don't see any advantage of the MSD plugs "YET" 😃

The two piece plugs may be a pain but it really is easy to extract if you break one. And since you have the tool,,,,,

It's been running smooth ever since I tuned it up. Improved throttle response an mileage.

So that's only my opinion on the plugs, save that cash for upgrades then get the better plugs later down the road.

V8StickConv

Thanks for the info. New spark plugs are going to be a definite improvement over the 10 year old plugs that I have now.

Derf00

I changed my plugs about a year after I bought my 08 (at around 10K miles) just so that I wouldn't have to worry about this whole mess of broken plugs. Went with the Champion one-piece 7989 and now have more than 60K worry free miles. I've popped a few random ones out over the last few years and miles just to check on them and have had zero issues with them.

I would never use the OEM two-piece in my heads. Just MHO.