More mis-information....

Just like everything else in life, you get out of it what you put into it. There is NOTHING wrong with the design of the A-500/A-518 transmissions except the owners who tow with them in OD and don't change the fluid/filter. Aside from a few failures that EVERY type of tranmission ever made suffers from, the 904/727 OD variant transmissions will live behind anything a normal 904/727 will live behind. Build the trans for what you are going to use it for and you will be just fine.

As far as the cost goes, buy a JY trans and build it yourself. Not that hard with a Service Manual and a few folks from this board helping with advice! That will bring the cost in MUCH less than a GV unit. The people who run a 500/518 in a muscle car will tell you what they think. Then make your decision....