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View Full Version : Headers for the 496 HO



blueliner
10-16-2006, 04:35 PM
what is everyone's opinions of the various headers that are available for the 496HO??? are cmi's the best?? what about the eickert cast aluminum, the hardin, stainless marine etc??? who has put what on their boat and did it deliver the "bang for your buck!!" what about installation with the various companies headers?? cmi seems to be the most popular, but is it the best with regards to the gains, ease of installation and what it promises to the dollar. just wanted some opinions before planning my off season upgrades.

thanks

BUIZILLA
10-16-2006, 04:36 PM
get the CMI's..

I think Trick marine has the best price i've seen so far.

JH

Cuda
10-16-2006, 06:23 PM
Does KE make headers for the 496? Some people think they are butt ugly, but I think they are cool as hell. I just couldn't pull the trigger on $3200+. I just bought some Dana's should be here Wednesday.

BigGrizzly
10-16-2006, 07:02 PM
I have CMI on two of my boats. One set of sport tubes on the Corsican with a 351 Ford Clevland- because they were the only people who would do it. the Criterion has CMI split top because the motor is 690 HP and can use them. However The elbow tops only lose 20HP and 1 lbs of torque. Stainles Marine Loses 30 and 3lbs of torque. So for bang for the buck stainless has it However Dana and the new Hardings havn't been tested by me so I can't give a answer on them. My system is Silent choice or captains call or what ever. will cost about $8000 retail. call for a price for youes. Mine look cool as heck

yeller
10-17-2006, 01:38 AM
Ahhh, the winter modification bug bites. :biggrin.:



.. IMO the 496 STOCK cannot take full advantage of the CMI's without further mods.. Stock....who said anything about stock...:lookaroun

Sorry Blueliner, have I put too much pressure on you to S/C. :wink:

LKSD
10-17-2006, 07:51 AM
Steve, I will have the #'s on the stuff we talked about for you this afternoon.. :) :) Jamie / Lakeside

Pismo
10-17-2006, 08:07 AM
I have CMI on two of my boats. One set of sport tubes on the Corsican with a 351 Ford Clevland- because they were the only people who would do it. the Criterion has CMI split top because the motor is 690 HP and can use them. However The elbow tops only lose 20HP and 1 lbs of torque. Stainles Marine Loses 30 and 3lbs of torque. So for bang for the buck stainless has it However Dana and the new Hardings havn't been tested by me so I can't give a answer on them. My system is Silent choice or captains call or what ever. will cost about $8000 retail. call for a price for youes. Mine look cool as heck

I don't understand a word of this........but I would like to very much

BigGrizzly
10-17-2006, 11:02 AM
Sorry pismo. I did Dyno numbers on my Procharged 502. These were the differences in HP numbers between The split tube and the Elbow tops and the Stainless marine Manifolds. The point is the smaller motor will show smaller HP losses.The biggest gain was fuel use is less with the CMI tube hedders.

blackhawk
10-20-2006, 08:20 PM
I have CMI on two of my boats. One set of sport tubes on the Corsican with a 351 Ford Clevland- because they were the only people who would do it. the Criterion has CMI split top because the motor is 690 HP and can use them. However The elbow tops only lose 20HP and 1 lbs of torque. Stainles Marine Loses 30 and 3lbs of torque. So for bang for the buck stainless has it However Dana and the new Hardings havn't been tested by me so I can't give a answer on them. My system is Silent choice or captains call or what ever. will cost about $8000 retail. call for a price for youes. Mine look cool as heck

How did you lose so little tq compared to hp? Were the lower rpm hp numbers similar and only the higher rpm numbers -20 hp?

BigGrizzly
10-22-2006, 07:26 PM
The reason is the torque band on my engins is so flat because of the cams I runand its supercharged. Forinstance the 502 has 700 lbs at 3977rpms at 5490 It has 667lbs. For boating I use hi torque combinations. I don't and won't run my motors past 5500 for more than 1 mabe 2 seconds at most My rev limiter is set at 6000 for unforseen issues, blown prop hubs or trans failures etc, You will also find these are high torque tyoes. I'm sure if I took the engines to 6000 or 7000 the torque would be greater. If I don't go there why bother. I also found that the torque difference made no difference in top end on the water. but I didn't do back to back test the same day, so I can't say there is a real MPH difference on the same day. Anyway this is what I have found. If anyone has a problem don't tell me tell the Dunometer. When Rootsy does his test with his profiles you will have a chevy small block numbers The Clevland has only had two types of exhaust on it and one was a log manifold so the difference was very big but can't find the paper work on it.