http://www.camaros.net/forums/showthread.php?t=141893
From JohnZ:
"Tonawanda had two completely separate V-8 lines - one complete system (machining and assembly) for small-blocks, and one for big-blocks. ALL big-blocks were built at Tonawanda. However, on the small-block line, they only built hydraulic-lifter engines, and didn't have the added machining stations in the small-block cylinder head line to add the unshrouding cut in the chamber wall required for 2.02" intake valves.
All small-blocks with solid lifters (and the few hydraulic-lifter engines that used 2.02" valves, like the L-79) were built at Flint V-8, which had the unshrouding-cut stations in their cylinder head lines."