To what spec are you building towards?? My car spec't out this year as a 2.4 legal to 6 flat and doesnt have the "K" or really need it there, But I do run the dia in the rear end bay and that bar can be removable for access to get the RE out. What you need to look at now is the seat bottom size. When I get a car in here that needs the Kidney bars and is of the 2 rail WOODY type I have had to bend the bottom of the 1 1/4 tube at the bottom to clear the seat pan. With how you have it now the chassie must be really wide or you are real skinny.