I had a GPASC 2180 back before they realized that the oversized valves were useless and a detriment. The replacements that I got from GPASC, were from EMPI. If you want good heads, get the ones manufactured under license from VW, note, that is NOT WW. The ones that I got were from Brazil with standard sized valves and never had another problem with them. However, my problem was not the same as yours. The exhaust valves in my heads were sinking into the head. The reason was because EMPI makes them with plugs in the valve recesses, to make it easy to remove after casting. This, plus the oversize, causes the exhaust to have less meat around the valve seat, than is necessary to remove the heat.
So, the message is get the right heads with standard valves and keep them cool. See N64KR at <http://krbuilder.org/> http://KRBuilder.org - Then click on the pics 2016 KR Gathering - Mt. Vernon, Ill. Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best KR at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Paint at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior and Panel at 2008 - KR Gathering in Mt. Vernon, Il - MVN Daniel R. Heath - Lexington, SC
