[Alan Roehrich]

Avoid using Tru-Arc retainers if at all possible. There is a very good reason that people use either round wire retainers or double spiro-locs, and it is not because Tru-Arc retainers are real reliable. Those things are "okay" at best for a stock rebuild, in a restored car that won't be driven a lot. In a modern race or high performance engine, they are a recipe/invitation for disaster.