I have been looking for a heater core for my 58 apache for a few years now. I bought two and they were the wrong size. One was too wide the other too long. Both were bought from owners of task force pickups that said they were exact fits. Thanks to Red 58 I got the exact dimensions for the deluxe hearer core and went on line to parts store sites comparing dimensions. Long story short I bought one for a 72 Ford pinto with air cond. It fit just right and my heater box closed with screws and defroster connected. The only thing I have to do is fabricate a bracket to secure the core inside the box. My inlet and outlet tubes went thru the firewall with no issues but my firewall holes had already been altered just a bit. I can't believe after all this time I will finally have a warm cab.