There is nothing wrong with a 318 engine. No one claims a 318 is better, just sick of 360's are better. I'll give you a clue about 360's. They also were not High Performance engines. They were high torque low rpm engines to push C Body cars around. I used to buy them, scrap everything but the heads and rods. I'd use the heads on 318's and 273's. The only reason for the High Performance 360 was, they discontinued 340's and had to drop compression for emission reasons. It was the last man standing at that point. Just like your HP 360, if you do the same for a 318, heads cam and other goodies, you will get the same hp, just at a higher rpm and less torque. No big deal. Air flow, seal the cylinder, tune it. I sold my last 360's decades ago to make room for my 340's and 273's.