I installed the 5/16" spacer and it was a relatively easy install. I have one question...will the white thermal-resistant post-spacers degrade over time with the heating and cooling cycles of the engine? Could it cause a problem in the future (say over 100k miles)?

 

This is a good question for Tony @ MotorDyne, call
and ask him this question. I have the MD 1/2"
spacer and I'm not concerned, and don't believe
it's an issue. (aka problem)

 

Thermal cycles in the 0-200 F range aren't a problem because it is formulated specifically for the application. The only problem for would be from UV. But there isn't much of that in the plenum anyways.