Yes you are right as I use the Hedman Elite 1-3/4 tube headers. 11.50's so far but I think it has at least 11.40's in it. My headers came with the car as my buddy who sold me the car had bought them and never installed them so they were brand new and never installed when I got the car. They dont seem to hurt my mild combo and and they might even help the low end as I sixty better then my sons Dart does and he has 2" tubes on his. You should be fine for a mild street/strip car with the 1-3/4 tubes. Ron