Happy New Year, Stuart...Pleased that you're getting the CompCams tool.  It's easy to use and intuitive.  New Melling and other source pushrods are available at a variety of lengths, which should make the selection process simpler.  Of course, there are also adjustable pushrods, but that's a more costly alternative.  Melling fixed-length pushrods sell individually, so you have the ability to precisely fit individual pushrods. In the heyday of AMC inline sixes, head work typically meant grin