My opinion 2-250 hours

im curious,what kind of performance gain can one expect to see with the swapping of the firing order in a marine application?

Mike,

From speaking with Bob regarding my cam, I came away with the understating that it's implemented (firing swap) primarily to reduce forces on the crankshaft, and that in many cases, it can add "some" HP. I think some people on the Internet have talked it up regarding hp, to something it's definitely not. I'm not quantifying the actual gains, just sounds like it's not as grandiose as some make it out to be.

Personally I was happy to learn about the reduced loads on the crankshaft. There may be other benefits I've missed, and as such I will leave that up to bob and those that are more familiar add to this.

i am not against a firing order swap but i dont buy into the claims of big hp gains.in a 10,000 +rpm pro stock engine a little gain in hp can be big but once one team realizes the gain they all do it.the guys that think they will see a noticable gain in performance in the marine world might be dissapointed .this is my opinion but im not one to buy into snake oil,i like results,not hype.

Was told smoother idle also. Dunno..

Generally you are right. The good news was since GM did the swap on the 8.1L, it made the cores cheaper and thus not much more money for someone with the standard BBC.

When it was a lot more money, it was not worth it.

It's a free benefit. Swapping the firing order evens out the load on the cam so that lifters are being pushed on opposite sides reducing core deflection. No performance gain at all, just less stress on the cam core and longer life with aggressive profiles and spring pressures

Do they sound any different with the 18726543 firing order?

Mine does not sound nearly as nasty as my previous cams. But, that also might be the grind. I really miss the crack of my old cams they were just raw. But, I didn't change cams for sound:(

Bob is correct. 4150 based 950HP Holley carb. http://www.summitracing.com/parts/hl...96-1/overview/ Works extremely well on the 502 motor. Mine started life as the carb listed, but modified. Now flow (flow tested) 1000cfm.