Why use 0.006" and 0.008" as clearance? The 0.006" and 0.008" is OK with a standard set up, but it isn't correct for pretty much any non-standard cam, with standard aluminium pushrods and iron barrels.
Do you know the full spec for this engine?
Maney specifies different valve clearances depending on which parts are in use. If you have his just his steel pushrods, he recommends you halve the valve clearance, if you also have his alloy barrels he recommends you close it to 0. Yes, 0, because the alloy barrels expand a lot more than cast iron ones.
Maney's cam is close to a 3S Norton cam, I'm not sure of specs, but with standard pushrods and iron barrels you would use around 0.011" inlet and exhaust. (This is the figure for the 4S and PW3 with standard pushrods, followers and iron barrel.)
If you just have his pushrods and his cam then set both at 0.0055", not the 0.011" in the cam spec. Typically, I would round that to 0.006" inlet and exhaust. So your figure may be OK.
