340 Cam Size

The cam in my 318 is the MP Purple P4452782. I was told that this is essentially a stock 340 cam...429/440, 268/276. I suppose I can just buy another one of those and a set of lifters and drop them into the 340. Won't be too awful exciting, but should be a solid runner. Thoughts?
It'll pull harder than the 318 by mere cubic inch and the wayyyy better X heads.