I just put the shorty exhaust system on the car and took it for it's first street blast post Thompson. In the home stretch about a mile from home the upper radiator hose blew a hole. The place it blew was right next to the oil fill tube, just under where the cap goes on. I'm not sure but I think it may have pushed some coolant past the cap into the oil fill tube. This is not good news. I use Mobile 15/50 full synthetic oil in the 409 at the track. I think the last time I changed the oil before the track it cost me over $55.00 bucks. Oh well! Cheap insurance I guess I did read that the Mobil 1 OW-30 and OW-20 race oils have twice the zinc/phosphorus content of the regular 15/50 oil. Maybe I'll try some of that and see if I reduce my ET!