This is the cap to use on all vertical radiators. This is a 7lb cap. This cap is he one that has a long neck that mounts on the radiator. Old tired caps can leak pressure and thus causing overheating. If your cap is the original - it is time to replace! We also now carry a Gates vertical flow radiator cap. If you don't have a vertical flow radiator, you'll want a stock crossflow radiator cap or a crossflow radiator cap with a safety latch.