I have got to replace my battery tray in my 72 K5, and i have noticed that it matters whether or not you have A/C? Why is this? I currently do not have A/C, but i will be installing Vintage air this summer. One more thing is i have got to modify the new tray in order to accommodate a new billet battery hold down that i have just purchased. I does not fit in between the sides of the stock hold down so I'm going to be cutting one side off in order to fit it.My question is should i buy one for a vehicle with A/C if I'm going to install the vintage air this summer? Thanks