Hemi Continues to quit at Speed.

Tin,
If I was looking at sensors, Id look at crank and cam sensors, but in my head I see a heat related failure taking longer to "reset", (heat would raise before it fell right?) so Im thinking voltage or ECU. It may be worth keeping a volt meter in the car and checking 12v + at your ign and ecu relays before you touch the key when it dies. Id also talk to hotwire about a reflash before you popped for a new ECU. You may even be able to see if one of these factory ECU guys would loan you theirs as a "known good" before you drop the cash...

Another thought may be what Tstat are you running? The factory 203* stat was hell on my underhood temps. I switched to a 185 and t has really helped my XFI system. You gotta reprogram the fans, but dropping 20* under the hood may solve the problem if it's heat related...

JOE