I don't know how thick they are, but you can buy shim kits also. I would check your lifter preload at the plunger, because the 3/4 - 1 1/4 turn after zero lash wasn't correct on my adj. rockers. but that would require removing your intake as well ( I assume you're running a carb ).
Yeah the pedestal are non-adjustable, and all the resources I have gathered say that 1/4-3/4 turn after zero lash to fully seated on the pedestal mount is the correct preload
I have this preload achevied with .030-.060 thick shims, and if the channel guides are .030 inches thick then it would be perfect for my setup, otherwise the pushrods may come out to be too short or the preload would be way too light.
It should work out though, I am ordering the kit online and will see how they work as far as thickness
Thanks for mentioning those things, I'd hate to be running without them. Are they pretty much required for running pedestal type rockers on my particular head?
The guides are .060" thick, and several of my rockers were shimmed to .060, which was perfect.
However, several of my rockers were also not shimmed or shimmed .030, causing a bit of a problem with lash. My valve geometry was correct before the installation of the guides, so to keep it simple I didn't want to order longer pushrods or anything (using 6.875, need 6.9-6.91 for some of the rockers), I decided to simply mill the required amount of material off the rocker pedestals. This keeps all the pushrods the same length, and while time consuming, a better way to go about it IMO.
Only did 4 cylinders so far, but it works great. When you mill the material off, you need to also do a *45 degree cut on the edges so that it will fit properly in the guides, sort of a bevel. The guides are stamped and bent steel, so the corners are not exactly 90 degree angles, more of a curve. The 45 degree bevel on the corner ensures that the pedestal will properly seat