I have the opertunity to get my heads shaved for 22$ a head. So my question is this since the engine i bought set for like 2 years is it possiable that antifreeze corroded the head gaskets ? Engine only has 96000 miles on it belonged to old man who used on his farm to hall feed to livestock. I did start the engine but did not let run long because it set so long.Antifreeze looked good as did the oil(still clean). So how far can i shave the heads if i have to put head gaskets on and how much more compression will it give me? Ea 82 carbed engine from 86 2 wheel drive car.

im not sure on subarus how big of a issue it is, but on some cars doing so has drastic effects on the cam timing because of the pulleys are now closer together. usually the cure is a belt a tooth shorter. otherwise you can get pretty ambitious.

i should mention the trick to finding out how close your engine is to interference engine is to put some modeling clay on the piston and bolt the head on and move it to top dead center and rotate the cam. measure how thick the clay is and thats about how mutch you can safely remove.