8 3/4 guru need your help

I have several cars with 8.75's, saying he runs 9.50 in a 69 dart is great, but is it running 9.50's in a factory weight 69 or is this like my friends 69 and it's 2800 lbs ?
Also he makes 300 runs a year or 6

The car weighs in at around 2800. My guess about 200 runs a season.