ICT Billet 551165 LS Swap Torque Converter Hub Adapter

When you drop an LS or LT engine in front of an older GM automatic, the crankshaft register that pilots the torque converter is a different size than the converter snout on a Powerglide, TH350, TH400, 700R4, 4L60/4L60E, or 4L80E built for the earlier small-block. This steel ring presses into the back of the LS/LT crankshaft and steps that bore down so the original converter pilots true and runs concentric.

It fits every Gen 3, 4, and 5 LS and LT engine (LS1, LM7, LR4, LQ4, LS6, L59, LQ9, LM4, L33, LS2, LH6, L92, L76 and the rest of the family). The one common exception is the 1999-2000 6.0L, which already has the correct register and does not need the adapter. Which flexplate and spacer you pair it with depends on your engine and transmission combination, so check ICT Billet's LS/LT crankshaft and flexplate guide before final assembly.

On the bench it is a two-minute job: seat the ring squarely into the rear crank bore, then install your flexplate and torque converter as normal. Getting the converter to pilot correctly is what keeps the pump bushing and front seal alive, so this ring is cheap insurance against a converter that walks and wears out the front of a fresh transmission.