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Discussion Starter #1
Got a set of Darts for a BBC that are currently 355cc runners. Is this head too big for a 496 cid 13:1 deal with a 250 hp n2o kit? Application is a jet boat, thanks
 

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If the boat is going to be over 6500 rpm and WFO all the time they will work. YES
If you are looking for mid range power with punch, NO.
If this is a pleasure boat with the occasional WFO pass, NO

To bandaid the cylinder head size you will need a very small camshaft.
 

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Discussion Starter #3
It is frequently at WFO! Are you saying a small cam as a bandaid for mid range suffering from the huge runners? The cam in it now is not huge, 262/270 @.050 ,714/714 @ valve, .020 lash, 109 LC with a 114 LSA. Factoring in the lash its below .700 lift now.
 

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I started a thread a while back on Good vs. Bad on Dart heads .. It was a good read, might wont to look it up :)hand .. I tried to copy and paste but didn't have any luck
 

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steelcomp was here
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Those heads are way too big for a 496 under almost any circumstances ...IMO.;)
 

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You already know my oppinion but Ill go ahead and state it here so someone can call me an idiot!! On motor they will be a little big and will need to wind the motor up to make good power but so be it cause it will still run better than what you got and when you turn the nitrous on it will pick up the slack, then when you get tired of you know who wearing your ass out:D and go ahead and step up to that 565 you will have the cylinder head you need.
 

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Stick a blower on top
 

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Discussion Starter #14
ok, i was planning on a 565 anyway but theres nothin like a test mule so i will get em in the shop, get em freshened up and stick em on the small motor just to see what will happen. Hell 2 more solenoids will wake em up anyway. Then when the 565 is done we can see the difference and I will know for sure. Thanks for the input fellas!!
 
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