Ok so some individuals have indicated there may be two versions of the plastic battery box on an M35A3, I currently do not have access to my truck to measure the box. Here is what I do know: NSN 6160014072852 PN 12368320 (I do not know if that is for the metal or plastic). The measurement for the ones for sale are 24" Length, 13" Height, 12" Width. I intend purchase the largest with the most CCA that will fit the box and I have a couple of options to purchase then drive a few hours to where the truck is being stored to install. I am just trying to avoid a "surprise" they don't fit, scenario.....Thank you for anyone that can confirm those measurements..