I posted this on Craig’s thread since he is about at the same spot on engine work, but am putting it over here to have a better chance of response from the V-12 expert team
I finally got my heads back from machining, tested the valve clearances and have ordered the appropriate shims, which are all .005-.008 thinner than the old ones due to the machining, but all still in the .091 - .099 range. I got a new timing chain and installed it, after adjusting the timing chain guides per the book. With the cam sprockets on the rests it is really tight even with the tensioner fully retracted, but i hope a little slack for the tensioner function is created when the cam sprockets are attached to the camshafts.
I noted that Craig and Wiggles installed the heads prior to installing the timing cover. I think the ROM has the timing cover going on first, although that would obviously mean the cam sprockets need to be resting on the supports until the head is on, and the chances of something going wrong that would require removal of the timing cover again seem pretty high to me.
I assume that the assembly order of 1) heads - 2) timing cover - 3) bottom end oil equipment - works okay? Is there a good reason to follow the ROM instead or anything in particular I should do in this stage? I think I have the timing chain hitting all the right spots on the sprockets, but understand some adjustment of the cam gears will be needed to match up with the timed camshaft. I have the Cometic head gaskets so i understand no sealant is needed there - except for the front bolts that are mentioned in other threads. I need to study that advice more.
If anyone has any thoughts on the above or see that I am about to do something dumb, please let me know.