OK, OK here it is,,, http://www.gearheadtools.com/tooltips.htm If you have removed a lot you might need to cut the ends of the manifold too. It's not critical (as long as it doesn't hold the manifold off the heads. Amount varies from 1.4 to 1.7 depending on angle. I like to get a fairly small gap and just use RTV to seal it. But hey,,, that's just ME!!! Bruce Hevner