We seem to have quite a few people working on their GM V8s with Engine Freshening or Rebuilding in the works right now. It follows that at some point... the Motors will need to be "Buttoned Up" at the Front and Rear Covers either with...or without the Crankshaft Oil Seals installed when that happens. The problems that can occur though come from the lack of any way to perfectly align the Covers as the OEM Seals get applied and then the Cover Bolts get run in home... possibly with more misalignment than should be possible. But... without having Fixed Gaskets with the Old Steel Alignment Guide Pins to make these covers behave... there is just a little too much "Wiggle Room" to guarantee that these covers are not misaligned so far off center as to have the Crankshaft Seals wallow out and leak way prematurely. The inexpensive solution is to use the Mr. Gasket Cover Alignment Kit that will serve to install both the Front and Rear Covers...either with or without the Seals pre-installed. This article and video gives a nice up close and personal look at what a difference these simple but important aids to a assembly can make:
Here is the Article... among a few other topics:
http://www.chevyhardcore.com/news/using-mr-gaskets-ls-cover-alignment-tools/
Here is the Article... among a few other topics:
http://www.chevyhardcore.com/news/using-mr-gaskets-ls-cover-alignment-tools/