dev2458

A few weeks ago I did spark plugs, valve clearance inspection, and everything from the validated parts list posted earlier in this thread.
The car is a 2008 IS-F with 114,555 miles.

I want to give a big thanks to lobuxracer and others for the tips and pictures. 
All but 2 valves on the passenger intake side fit the go no-go method that lobuxracer described earlier in this thread. 2 intake valves on cylinders 2 and 4 were just above the limit, see the pictures below.
0.008" feeler gauge fit very tightly, but 0.009" did not fit at all. 0.00709" is the max clearance.
I did a few pulls before parking the car, but maybe I should have done a longer drive to get as much carbon as possible off
I am not going to adjust the valves unless someone suggests otherwise. The car is stock, and oil change intervals has been every 5k miles, except for a few 10k intervals synthetic from previous owner. This bothered me until I read other threads and seeing people with 12k OCI doing just fine.

Some notes from the job I can add to help others. I used "steering rack wrench" (09617-24011) to torque the 22mm HPFM connections. The service manual has torque values for this special tool. Taking off the nut from the HPFM without spinning the lower part was a lot easier than I thought, just make sure you hold it tight with a wrench.
Disassembly of the ECU box looks daunting but isn't too bad. I put a small amount of the FIPG (00295-00103) where the timing cover meets the cylinder heads, not sure if necessary but the service manual has it and I had some laying around from a previous job.
Some of the valve cover bolts are hard to reach, and seemingly impossible to torque to exact spec. I used various wrenches to get as close as I could.
I made sure to take pictures of all fuel line connections so I didn't connect them backwards. I WAS ABOUT TO CONNECT THE DRIVERS SIDE BACK INCORRECTLY! Luckily I consulted the pictures. The lines are very easy to switch. I made sure to not flip the left and right side HPFPs.
The HPFM studs came off with an e-torx bit easily. All of my wire harness zip ties came off the studs easily without breaking. Both of these surprised me after reading lobuxracer's experience.
None of my coil pack connector tabs broke when unplugging. This was very surprising becuase on my IS250, 5 out of the 6 broke. The job took me a weekend and about 16-20 hours. I was taking it very slow.

Here are some pictures:
Valve clearance measurements on cylinder 2 and 4s intake valves:

Valvetrain passenger side:

Valvetrain drivers side:

Underneath valve cover, as lobuxracer said, "this engine is not unhappy"

A picture with all parts replaced. It cost $257.83, and $93.60 for 8 spark plugs for those wondering. I wish I waited a few weeks to take advantage of the 17.76% discount Lexus was running.

Seeping passenger side HPFP gaskets before job. Unfortunately I don't have a good picture of the drivers side but it was worse:

Spark Plugs with oil from worn out spark plug tube seals. Cylinder 5 was bad. These were changed at 63,285 Miles on 12/11/2015 according to the maintenance history from lexus.com:

Quadrphnia

Excellent job. My hat's off to anyone brave enough to do this at home. My hands have gotten lighter over the years, but far too heavy to attempt this on my ISF. Going to practice a valve adjustment on the snowblower this month.

Tube seals were shot on mine as well at around 50k & I had them taken care of on CPO. This is the trade off you get for having a strong dealership record & strong Autocheck/Carfax report - techs that rush through the simple things and overfill our cars with oil.