I have a Neal Chance all aluminum converter in my Nova. It reduced the rotating mass by 6 lbs. Sixty foots dropped from 1.14 to 1.06 and ET dropped from 7.06 to 6.84. Cost a lot of money but well worth it. Easy to change the stall by moving shims. Have a spare stator incase I'm not running nitrous. You can clean the thing out yourself if theres a transmission disaster.
Marty Chance is a great guy. Check out the pics of the converter on my RJ profile below.