It can be done with a stock tank but it is tight. My springs are moved under the frame and I have a stock gas tank and the 3 inch TTI exhaust system. The TTI system did not fit out of the box. It cost me $1000 for a street rod fab shop to cut the TTI system all apart and reweld it so it would fit and work properly. So add that to the price tag. I think it would be cheaper to just have a full custom exhaust built rather than buy a kit that doesn't fit and have to spend a lot of time making modifications but maybe their kits do fit on other cars.