ITEM NAME:Replacement Flexplate Adapter Spacer for GM TH350&TH400 LS1 LS2 LS3 LS6 LS7 Description: Easy install,direct replacement. Flexplate Adapter Spacer for GM TH350 TH400 LS1 LS2 LS3 LS6 5.3 6.0 LS7 700R4 When installing a Th350 or Th400 behind a LS engine while using a curved flywheel you'll need this adapter spacer. The spacer will center the nose of the converter to the curved flexplate. For use on LS1 based engines using a TH350 or TH400 transmission. Specification: Outer Diameter: Approx 50.8mm Height: Approx 25.4mm Package Includes: 1 Piece Flexplate Adapter Spacer Note: Please allow 0.5-1 inch difference due to manual measurement.(1 inch=2.54cm) Please check the size measurement and the picture carefully before making.Flexplate Adapter Spacer for GM TH350 TH400 LS1 LS2 LS3 LS6 5.3 6.0 LS7 700R4. For use on LS1 based engines using a TH350 or TH400 transmission. When installing a Th350 or Th400 behind a LS engine while using a curved flywheel you'll need this adapter spacer.