Why does a 1999–2000 LQ4 need a different flexplate?

Most LS engines have the crank flange farther forward than an old small block, so swapping to a TH350/400/700R4 uses a dished flexplate plus a converter sleeve. The exception is the 1999–2000 LQ4 6.0, which has a "long" crank flange and uses a flat flexplate with no dish or spacer (Speedway Motors). Confirm your crank before ordering adapter parts.