On slicks. Same setup at previous race. Only changes was the hood and air cleaner. I absolutely believe the biggest factor to be weight however I could tell the car was down on power as well. I didn’t want to risk running without the air cleaner because of how close the carb is to the hood and despite the fact that I tried to clean it out as much as possible, what sentiments could be trapped in the 55 year old hood that could fall out and get ingested.