Fits Ford Radiator Cap 4 PSI NAA Jubilee 600 601 700 800 801 900 2000 4000 1T810Fits Ford Radiator Cap 4 PSI NAA Jubilee 600 601 700 800 801 900 2000 4000 1T8100A Designed for 4 PSI Pressurized Systems with a 1 1 2" Radiator Neck Inside Dimension. Replaces the Following Part Numbers: Fits Ford 1T8100A2 Fits Ford: 2N, 8N, 9N, Jubilee, NAA, 2000 3 cylinder, 2000 4 cylinder, 4000 3 cylinder, 4000 4 cylinder, 5000, 501, 515, 530, 531, 532, 535, 540, 541, 545, 550, 555, 600, 6000, 601, 610, 611, 620, 621, 630, 631, 640, 641, 650, 651,