LS Piston Ring Squaring Tool Pair

After placing the piston ring in the cylinder bore, use this tool to insert and align the piston ring to a set depth to accurately check ring end gap with a feeler gauge.

Sized for 4.8L/5.3L LS engines with a 3.78"/96mm bore, but can be resized in your preferred slicer for different engines.

The first tool inserts the ring to a depth of 20mm, the second tool inserts the ring to 69mm. (About halfway down the bore on a 4.8L/5.3). The short ring gap tool can also be inserted at the bottom of the cylinder bore to check ring gap at BDC. For a home engine builder, you can use both tools to check ring gap at TDC, midway, and BDC in the cylinder bore to determine a rough estimate of bore concentricity before any necessary machine work.

2.25.26 - I added a third gap tool that inserts to a depth of 25.4mm, which is the proper depth according to the Indamar service manual.