He's talking about the sheet metal locking tabs that were installed under the original small block exhaust manifold bolts. Once the bolt was torqued, a tab was bent up onto a bolt head flat, supposedly to keep the bolt from loosening up. They were worse than useless. Most of us who made a living wrenching on Chevy engines back then had a 9/16" deep socket with a bevel ground on the end so we could hammer it onto the exhaust bolts and release the locking tabs.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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