here is a good site for subaru engine specs
the subaru headgaskets are metal.
my tech. and i figure subaru put the thinner gasket on the phaseII to compesate for switching to sohc by upping the CR a little.
he says the thin ones are terrible compared to the old thick ones.
using numbers from the ejcalcs site and here:
and plugging them into here:
i got a cr for my franken subie project idea of 11.64:1 with the thick(dohc) gasket and a cr of 14.32:1 w/the thin(sohc) one.
here are the numbers for ej25 converted to inches for you so you can enter them into the site quicker. get the head volumes from ejcalcs.
gasket thickness(thin) 0.0228346"
gasket thickness(thick) 0.0598425"
gasket bore 3.9173"
cyl bore 3.9173"
intake closing point deg ABDC 52 deg.(this is for ej22 heads)
got pointed to alot of this stuff by my guys at the legacy central bbs.
so the head gasket makes a big difference on subarus.
go old school scoobys!