I have three 340s, and have built many more. One 340 has been machined and sitting on an engine stand, and is still there after 20 years, waiting for me to get tired of my HP 273. What is your point? The OP asked:
What are you helping him with? Post #17 gave him 2 cam recommendations, one put out 280 hp using his stock 318 engine. You answer with get a 340 or 360. I don't see where he asked what engine he should swap in.