you would be better off to build yourself one than to buy one all of the factory diesel cars were built with converted diesel engines that are basicly junk and are prone to cracking. You would be much better off puting a 6.2 or a 6.5 out of a chevy or gmc truck. These are better engines that were built by Detroit Diesel and have basicly the same size and weight as a stock big block chevy and even use the same motor mounts.
I just so happen to own a factory diesel el camino its white in so-so condition. it is currently not running but i am about to have someone come and fix her up. are you still interested and if so where are you located?