If you go by factory ratings, few believe a 340 makes 275 gross hp.
Plus 340 has more like 9.5:1 then 10.5:1 so it's around one cr point higher than a 318, good for about 5-7% power increase and a xe262 cam is a lot bigger than a stock 340 cam, main difference would be heads and which nether is being a restriction at that power level. So 340 better cr and heads/ 318 better cam and headers. And if you want to go by stock gross hp figures a 318 was rated 230 so a cam, 4bbl and headers can't add 45 hp?
