SUBARU EZ30 H6 High Performance valve spring set to suit stock retainer. 

Short spring installs on intake side to give 76lb at 31.2mm, coil bind 19.05mm . Add base supplied to Exhaust side on top of OEM base to give 90lb @ 37.0mm, coil bind 26mm.

Note: Second Gen only! Engines with variable lift cam shafts and plastic intake manifold. EZ30R, EZ30D.