I have to agree with the last two comments. It appears the top portion (the fuel dump/flapper), is consistent among all competitors, Ford, Chevy, etc. I do see different bottom portions among the other teams/cars. So, it is possible that the top was 'common' and the bottom portions were made by each of the teams. It appears likely on this since I have seen Hollman & Moody tanks and oil coolers used on Fords and Chevys. Jon, what do you conclude?