Look what I found on Ebay. Might save someone alot of work. I have seen some guys on here doing some transplants. Eventually I plan on swaping a Gen3 motor into my mustang.

http://cgi.ebay.com/ebaymotors/LS1-LS6-GEN-3-UNIVERSAL-MOTOR-MOUNTS-STREET-ROD-RAT-ROD_W0QQitemZ230079152731QQihZ013QQcategoryZ50454Q QrdZ1QQcmdZViewItem

http://i3.ebayimg.com/03/i/05/49/8a/bd_1.JPG
http://i16.ebayimg.com/04/i/05/43/36/e7_1.JPG
http://i1.ebayimg.com/02/i/05/44/22/28_1.JPG

decent price too :judge:

transdapt has them and they cost about the same.

I saw some one that came with like a ~2 inch adjustment, so you could actually slide the motor fowards and backwards a couple of inches. I can't seem to find them again. That way you could get the motor position right up next to the firewall. If anyone has seen these please post a link for me.