I think he's slightly mistaken. the oil cooler return line on every cop car I ever worked on was through a special hollow fuel pump bolt. The right hand side (front bolt). This allowed the cooler, returned oil to hit the timing chain on its way back to the pan. It's quite a brilliant design.

So that's what he's probably mentioning. I could be wrong, but there was never any production line fuel cooler. The possibility of a dealer-added on gimmick or cop garage mod is certainly there... but I doubt that. Fuel doesn't heat, and adding a cooler near the engine bay is only going to induce heat soak when idling for long periods of time or leaving the car parked. something cop cars do a lot of