I purchased an aftermarket heater core for my '66 Chevelle. Although the aftermarket heater core dimensions are exactly like the original, the tank profiles are different enough that my original hold down clips will not work. I plan on fabricating new clips to hold it in, but also need to prevent shifting up and down / side to side. Anybody else run into this and what did you do? Thanks for the help, Krister Meister '66 SS #'s matching
