I use to help several different SB Mopar NHRA Stock and several different Mopar Super Stock class racers years ago, several of them held the NHRA records for their classes Gene Buehl held the E/SA for two years a long time ago Same thing later in C/SA with a different car but not as long.
All of those type cars are very high maintenance, not easy to make them run faster either
Go back to the basics and try to figure out what went wrong and when it started to go downhill
The car and time slips are talking to you, the hard part is trying to figure out what it is saying exactly and understanding what is causing those changes on the cars performance
Do you buy fresh racing gas for every race? If not try starting with that
IHTHs