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Jeff Jewell · 04-02-2016, 03:10 PM

While I don't have an answer on the RPM level, I had an interesting observation with my oval port headed 427 BBC a couple of years ago. This combo was shifted at 7400 and trapped around 7600. I had a standard roller cam in it when I had to pull the engine early due to a cylinder head issue. When the engine was taken apart, we found the cam was soft and starting to wear prematurely. The cam manufacturer had a bad run of standard cam cores. They couldn't get me a replacement in a standard cam right away, but they offered me a replacement in a 4/7 swap (no charge for the replacement cam BTW). The cam was identical to the original cam, except for the 4/7 swap. Put the engine back in and the car ran exactly the same. No gain or loss. Only change I saw was that the engine seemed to idle smoother.

04-02-2016, 03:10 PM	#3
Jeff Jewell Member Join Date: Jun 2002 Location: Bangor, PA Posts: 182 Likes: 41 Liked 171 Times in 36 Posts	Re: 4/7 swap cams While I don't have an answer on the RPM level, I had an interesting observation with my oval port headed 427 BBC a couple of years ago. This combo was shifted at 7400 and trapped around 7600. I had a standard roller cam in it when I had to pull the engine early due to a cylinder head issue. When the engine was taken apart, we found the cam was soft and starting to wear prematurely. The cam manufacturer had a bad run of standard cam cores. They couldn't get me a replacement in a standard cam right away, but they offered me a replacement in a 4/7 swap (no charge for the replacement cam BTW). The cam was identical to the original cam, except for the 4/7 swap. Put the engine back in and the car ran exactly the same. No gain or loss. Only change I saw was that the engine seemed to idle smoother.