LA360 initial timing too high - are there different timing covers?

Just to update... Installed the Comp 260H cam this weekend. I installed it straight up, and double checked with a small homemade degree wheel. Based on this homemade setup, CCL and open/close were about 2 degrees retarded. But I figured that could be well within the margin of error with my equipment, so left it as is instead of trying to change things without data I was more sure of. After break-in, it now idles smooth @ 15 degrees initial advance. Compression went up some, ~ 120 on the two I checked. Still need to better adjust the carb, but all in all a much better running engine. Thanks for all the help.