It's a 4 main motor for starters, so some might see this as a reliability concern. That said, there are plenty of old truck sixes much larger with four mains... Also, the vehicles it was fitted to might be either junked long ago, or be subject to one of either faithful restorations, or hotrodding including a different motor.
The 240/300, being in production until comparatively recently has still a genuine "work truck" aspect to it, so enhancements are perhaps more common to simply add a little power to a practical vehicle.
The fact that stuff doesn't immediately present itself should not deter. You can have an electronic distributor made up, headers are probably on someone's list, and cams could be reground to performance grinds. A cast iron intake manifold can be brazed to fit plates mounting twin carbs, for example. Bellhousings could be modified or adapted to fit later boxes. Just because you can't call up and buy it like parts for SBC doesn't mean it's difficult!
There's plenty to work on, and a customised original 6 cylinder motor would be an interesting part of such a vehicle as the '61.
Regards, Adam.
