In 1998, and speaking of transmissions, you had no turbo 350 or 400. The transmissions in a 98 Sierra would be 4L60E(1500 series), or 4L80E(2500/3500). You want to change a ring gear, are you perhaps talking about the rear differential ring and pinion? The only other ring gear would be flexplate/flywheel ring gear, and it is usually changed as an assembly, fleaxplate for auto, flywheel for manual trans.
Wednesday, April 14th, 2010 AT 9:25 PM