I ended up using the VHT line of rattle can high temp primer and cast aluminum for my transmission and engine. It turned out very close to the color of the raw aluminum.
I am very happy with the rules and price.
http://m.autozone.com/paint-and-body...el/465005_0_0/
Take a look at post 140 for some pictures of my results.
https://lateral-g.net/forums/show...=33484&page=14
