Andy, Here's what one racing prep business does:
"Stripped and Acid Dipped. Everything is removed from the car, including wiring harnesses, and the entire tub is submerged in a caustic solution to remove all adhesive, undercoating, seam sealer, body filler, and paint. If rust is present, a diluted acid solution is used to remove it. The process is neutralized with water,
and a coat of oil stops the chassis from rusting until the painting and body work are done. This process is the most effective and cost-efficient method of reaching bare metal. With all sealers and coatings removed, the car is as light as it can be, and in addition, all hidden rust is uncovered and eliminated.
We highly recommend that the chassis be powderpainted after this process. Cost is based on weight, $1.75 per pound."
http://www.autometricsmotorsports.com/products/911/index.htm#3-Transmission: