273 Supercharged...ITS HAPPENING PEOPLE!!

Have a look at this thread and see Bill Dedman's post where he talks about what he learned from a guy who has a lot of Torqueflite experience - 273's tend to wind high, so, that bit about 'above 6000 RPM' may be relevant to your build:

http://www.forabodiesonly.com/mopar/archive/index.php/t-50518.html

Also, this thread is interesting:

http://www.forabodiesonly.com/mopar/archive/index.php/t-288545.html