The manufacturer's service manual is the most authoritative document there is for an engine, which is exactly why a wrong number in one is so dangerous: nobody double-checks it. But these manuals are written, edited, and in GM's case partly scanned from older paper, and mistakes survive into the published spec sheets. A decimal lands in the wrong place. An inch column gets copy-pasted from the row above. A figure is transposed when a page is digitized.
We caught 5 of them in the 6.2L LS3 V8 specifications. None is a matter of opinion: each one is internally contradicted by GM's own metric value or by the same dimension stated elsewhere in the same document. We show you precisely what GM published, the value that is actually correct, and the arithmetic or cross-reference that proves it. Every correction cites its source and is reversible, so you can verify it yourself.
GM's own metric value (103.241–103.259 mm) and the Block section's Cylinder Bore Diameter row both equal 4.0646–4.0653 in, so the published inch figure is a typo.
0.3 mm converts to 0.0118 in, so GM's inch figure is off by a factor of ten (a misplaced decimal).
the 15.0 mm tap depth converts to 0.591 in; GM's inch column repeats the M8 holes' 0.688 in (a copy-paste).
the 19.0 mm tap depth converts to 0.748 in; GM's inch figure transposes the digits to 0.784.
the 15.0 mm tap depth converts to 0.591 in; GM's inch column repeats the M8 holes' 0.688 in (a copy-paste).
