Disregarding HP & torque, the 304 is a great engine. The lower block is dimensionally identical to the 360, 390 and 401 AMC engines, but the 304 heads have smaller valves and you can't easily run the larger 360/390/401 heads because of interference problems. But the 304 is a very good engine in its own right. It just won't produce as much improvement as its big brothers if you try to hot rod it.
It has slant plugs, distributor in the front where you can get at it, good exhaust port design. There's a lot to like. Pay attention to oiling. The oil pump housing is integral with the timing chain cover, so to replace the oil pump you have to replace the entire front cover. Pump body is aluminum and the pump gears are steel, so replacing just the gears won't solve anything. The oil pump gears should extend ABOVE the pump housing by a few thousandths, to make up the gasket thickness so that when the pump is assembled there is minimal clearance netween the ends of the gears and the pump cover plate. You don't want an interference fit, but you also don't want a large gap.
Stock timing set uses a flat chain and the cam sprocket has nylon teeth. If it has that, scrap it and replace with a Cloyes roller timing set that has all steel gears. The nylon teeth can strip off and let the engine jump time.
Carbs do tend to starve on steep inclines and cross slopes, but there are fuel injection options for the AMC engines. Edelbrock just released a new multi-port injection for them, and there have been throttle body conversions available for several years. I just recently saw a thread on this topic on another forum, and the consensus was that for wheeling a 2-barrel carb is better than a 4-barrel. I'm not sure I quite buy into that, but that's the consensus on that thread. I'm biased toward 4-barrels because that's what I always ran ... but I was running street and race cars, not off-road trucks.
