I finally installed the SP-534 plugs I bought last April to go with my Livernois tune. I knew the plugs in the car were new when I bought the SHO in 2015, so I wasn't in a hurry. They were the same part number, and looked clean, but the gaps were all .035. I also added a half quart of fluid to the transmission, so I am now ADA compliant... I mean Livernois compliant... for the V11 93 Performance tune, which also went back in today. It doesn't seem as insanely quick as it did last year when I first installed the tune, but maybe it's just that the car needs to relearn my "tuned" driving style again. I took the tune out when all of this V11 shift controversy started. It seemed to shift just fine today, but it also shifted fine when I first installed the tune last year. My two test drives today just haven't been enough to convince me that it's fixed. Time will tell.
Coincidentally, when I first fired the engine after installing the plugs, just before installing the tune, my "Change Oil Soon" reminder came on, and reminded me every time Livernois had me turn the key to run. Annoying! I know, I could have reset the timer to 100%, but I was anxious to get the tune installed. My test drive was to Walmart to buy oil/filter. 48,335 miles - reminder for later.
What a PIA it was changing plugs 1 and 3. I gave up yesterday, and gave it another shot today. Success. Not for the faint of heart, or someone with massive hands. Plus I have ZERO strength in hands anymore, so I was using everything I could find to lever the coils out of those holes. Also had to Macgyver my old spark plug socket (ran a piece of twine through the center) to hold the plug for installation, since my new plug socket would not come off the front three plugs without use of needle-nose pliers. Thank goodness for abundant and/or worn out tools.
I used to love working on my own cars, but I no longer have the arm strength, back, hands, or vision I had when I was younger. PTU fluid change... I'll tackle that in the spring. Need to order the fluid from Amazon.