My feelings on the converter slip thing are.... for a “race car” with a race converter...... up to about 10% slip isn’t uncommon to see....... even in cars that run very well.
However....... 8% out of a 10” street converter in a car running “enough” gear is pretty high.
My friends old GTO Stocker with an auto.......
433hp(on the dyno), 3600lbs race weight.......5500 stall 8” ATI, 4.56’s, 9x30 Radial slicks.......11.33@117, low-1.50’s 60’....... 6000 shift, about 64-6500 thru the lights.
My 383(485hp) in my car(3670lb B body) with the flat steel hood on it went as good as 119mph, 4.56’s 9x29.5 radial slicks, 68-6900 out the back.......8” Dynamic, 5400 flash behind that motor.
