as above, am just about to do a compresion test on my scooby, what i need to no is what reading is a good reading

 

all cylinders equal within about 10 psi is a good start,

 

From memory mine all read between 150-165. That's a MY98 WRX wagon engine. It's a bugger to do though, being as by the time it's cool enough to work on and you've pulled everything out the way to get at the plug holes, the damn thing's most likely stone cold again when you crank it. But as above, it's the similarity between the cylinders that's the thing to watch.