one between each intake and exaust port, some are a litle lower than others. if you take off the exaust, carb linkage, choke, fuel, and pcv lines first they come right off. i would change the outer alignment dowels to studs while it's off. if you don't have a straight edge and feeler gauge to check straightness a machine shop should be able to do it for you. they need to be milled lots of times. a exaust leak is a pain on these, i just got done fixing one.
