Anyone have personal experience with this thick gasket? Does it really lower the temp? Install difficult?

 

Simple install. Took about 2.5hrs or a little less. Intake manifold still gets hot but not as much as before.

 

This gasket seems to help but I went a step further and also bypassed the coolant lines leading through the TB. Now the intake manifold seems to hover around the same temps as the surrounding underhood air which is cooler than the ~200* F head temp. When it's 90*F + outside the underhood temps are still pretty hot so just going by feel it's hard to compare easily. However when you compare it on a 40* F day and go for a drive, if the underhood temps stay reasonable you can grab the intake manifold and it will be cold while the head/valve cover is very hot. Datalogging wise I noticed about a 10-20* F drop on the intake manifold temp sensor while driving but that is somewhat fishy for accuracy since it heats up quickly due to heat soak in the engine bay. Probably if there was some way to vent fresh air over the intake manifold it would be closer to the outside air temps all the time when driving which is about as good as you can expect.