I'll back that up. Chrysler did some testing in the mid-'70's and that's what they came up with. Car weight was adjusted as needed and transmissions were built the same with the respective converters as close as possible.
I doubt I have 500hp, but I've been footbraking my 3,540+ lb car to as fast as high 11-teens @ 116mph + with 1.47 60' times with a 904. (Has a little more in it ;) ) Weight is a factor, but it's been working fine. For me the sprag has been the rare weak link in any Torqueflite. JW Transmissions in Rockledge, FL has been doing my transmissions for decades!
.15 in ET isn't anything to blow off!
While others as well as myself have done it, I've been told that a full manual valve body may not be a good idea on the street because of the constant hard shifts.
