Mugen raises by 0.4 points
plus if you have alot of carbon build up on the top of the pistons, that'll raise compression too.....
^^^(Not making this up, it's an ASE question....)
I don't have any in stock, and it'd probably be about a week or so before I could get you one, but you might try
www.performance-online.com if you ever need parts in the future
Scott Boller