[JJLT1]

yes,, haveing to clearance the block for a double roller chain is normal with some blocks..:texas:

i never had a line up problem with a Cloyes set,,
does the block look worn behind the cam gear??
which timing chain set did you get??

Cloyes shows a .031" wear plate also,, instead of the thrust bearing at .150 thick..
http://www.summitracing.com/search/Part-Type/Camshaft-Thrust-Bearings/Make/CHEVROLET/?Ns=Rank%7cAsc

http://www.summitracing.com/parts/CLO-9-201/http://www.summitracing.com/parts/CLO-9-201/

any machine shop should be able to cut the gear down for the bearing..

 

[JJLT1]

the bearing or wear plate is bigger than the cam,, it rides on the slotted part of the gear..
between the gear and the front of the block..

the back of the gear is what gets machined down for the bearing..

keep in mind tho,,
if you just shim (wearplate) the gear out you also change the wear point between the cam and lifter..
i would think??:dontknow: you would need to shim the gear to cam also :dontknow: ?? anyone ??
as said i never had that problem.. check the front of the block for wear..

i think your valves were too tight,,
i never liked that set all the valves at one time procedure..too much room for error,
when i set valves i do it one cylinder at a time..:texas: