Hey guys I'm putting in a new cam and to figure out my new lash pad height I took the difference between the base circle of my stock cam and of my new cam, this came to 2mm. I then added 2mm to all my lash pads and came up with the figures. The problem I'm having is that motorsport sells these in specific sizes which aren't identical to my calculated needs. My question is should I error on the larger size (ie. round up), or on the smaller size (ie. round down). Seems that the difference between the two will create a .15mm increase, or a .9-.11 mm decrease in height from the position the mechanic set it at which was at .30 mm of lash(cold). Thanks for the help

It's hard to just say which way to error. You'd need to perform a wipe pattern test to see which thickness would be best for you. Get one of each thickness and check the wipe pattern. Whichever thickness puts it the closest to the center is the one you want to go with. Test this on all the lobes to make sure you have the right size all the way down.

Here is a link to the same subject previously discussed:

http://www.classiczcars.com/forums/showthread.php?t=6342&highlight=wipe+pattern