Re: Need to get thicker lash pads...how much thick
Some confusion here. I think the figures you are quoting are actually your valve clearance figures. Lash pads are used to change the geometry of your rockers.
Normally not needed unless you change certain things such as:
Shaving your head
Increasing or decreasing your head gasket thickness (not likely).
Using new/changing cam towers.
There are other reasons. Here is the deal. You are trying to keep the wipe contact pattern of your rocker where it meets the cam in the very center of the rocker. If your vavle is adjusted properly, and the contact point is in the middle of the rocker contact area, you are fine. If it has moved towards the front or rear of the rocker, you need to determine if a thicker or thinner lash pad will move it in the direction you want. Have a look at one of your old rockers, and you should be able to see where it contacted the cam. That is what you are trying to adjust.
You may not need new anything.