Originally Posted by BDW
Check out this link, everything you need to know for 500/518.
If you go this route, get the 518, it's like having a 4.5 spd.

http://www.cuda-challenger.com/cc/index.php?topic=84774.0


If you want a low first gear you can only get it standard in a 42/44. The 518/618 has 2.45 low like the 727.
Plus the lighter internals are worth some e.t. especially behind a small block.