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Old 08-01-2013, 03:04 AM   #9
Scooby Specialist
Member#: 216984
Join Date: Jul 2009
Chapter/Region: NWIC
Location: Coeur D Alene, ID
1996 Impreza outback


Originally Posted by bigthoogs View Post
well i bent the valves on one side of my motor due to a bad timing belt. bought the car this way not to my knowledge. thought it was just in need of a tune up because it drove fine.

i know the combustion chamber will be too big thus lowering the compression ratio but im just wondering if i can run those heads on there with a stock gasket and be fine because id like to have dual port exhaust and i have plans to turbo the car and i hear the lower compression ratio makes it better for Forced induction.

i keep hearing mixed opinions on what will fit and what wont. just trying to clear it up.
Well, your car has a phase 2 engine in it so the phase 1 2.5 heads are out. Putting the phase 2 2.5 heads on the 2.2 block won't work because of the difference in bore size and combustion chamber width. Though in reality it would lower the compression some to a better level.

Since you want to do a turbo, the only thing I can think of is finding a used good condition sti shortblock and putting the phase 2 2.5 NA heads on that block with the stock 0.040 head gasket. Should be no higher than 9.0:1 but most likely a bit lower than that. I would double check on the stock phase 2 2.2 head gasket thickness though as I am not sure if it is the same as the phase 2 NA 2.5 stuff.

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