We'll be using my C10 project as a learning experience at the DIYAutoTune.com shop, and we'll be glad to share what we've learned with the community. One of these is motor mount templates you can download, print out, and use to drill and tap a piece of 1/4" steel plate to make LS to SBC adapter templates.
Downloadable LS swap templates at DIYAutoTune.com
First one up will move the bellhousing flange forward 3", but lets you keep the stock truck A/C compressor. We're going to see if it's possible to make a second adapter plate to go on the bottom of the mount to move the engine back to its stock location. Other templates are also going to be added as time allows.