Phenolic intake manifold spacer for Evo 7-8-9.   Originally had a sheet. 3/8 or 10mm thick. And made 1g and 2g spacers. Then made some for the Evo.  Heat reduction is pretty drastic. Plenum and runners remain much cooler.  Heat transfer from the cylinder head is much less.   The increased runner length with the spacer on the dyno increased 4-5 Hp consistently on a 310 Hp Evo.  Was only looking for the temp drop.    They fit in a medium USPS flatrate box. Price is each. Or buy both as package deal