I see your point. If I was running a 360 I would have went with the 500. Pretty sure my 440 would shred a 904 or 500 unless I spent big bucks upgrading them though. I've got two years and about 30 hard passes on my 518 now with no issues. Mines non lock up so it uses the same converter as a 727 so I was able to go with a 9.5 inch 4000 stall. low 11s, 3000 rpm @ 65 mph with 4.57 gears and 12.5 mpg on the highway plus I drive it to and from the track. The 518 install cost me about $3000 including the converter, JW Ultrabell and B&M Pro ratchet shifter. Great bang for the buck.