The aramid gasket replaces the steel stuff. Competing units we have seen don't include this gasket.
The lower plenum is put in place.
Howard uses an inch pound torque wrench to carefully torque the lower plenum to spec. It is a thin casting and you don't want to warp it.
Next Howard installs the provided longer bolts and spacers. It is here where we solve the mystery of the competing spacer's lower than stock power. It did not have any of the spacers so when the plenum was bolted together, it probably warped causing leaks. Not huge leaks that would cause a loss of idle control but enough leaks to possibly make the engine run lean and to harm the manifold's resonant tuning.
Loctite thread sealer is provided to reduce the chances of vacuum leaks.
The spacer is lowered into place.