I have a 1970 rt charger 440 4 speed when it was bone stock the best I ever got out of it was 14.10's in the mid 90's mph. A lot of practice leaving with the stick netted et. Mr. p is correct factory "muscle" cars left with 3/8 line. My biggest problem in that configuation was the factory fuel filter and pump. The filter had that built in vapor separator. It would lay over in 4th. Replaced the fuel pump with an hp Carter and filter with a regular 3/8's one and plugged the vapor line back to the tank.