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thinking about LS swap from twin 454???

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Old 10-27-2018, 01:01 PM
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Default thinking about LS swap from twin 454???

Hey guys, i have a scarab panther 30' that i have the twin 454ci motors out of it, i was going to build them up NA to make about 680ish hp.
Im a LSX guy here and prepare many LS builds, head porting and specialize with the LSA's LS9's LS7's, LS3's and so on, big with the cts-v's and zr1's.
So im up in the air if i should just keep it simple and build up the original motors or swap out for the new tech....i can put together a pair of stock bottomend ls3's that make roughly the same in power, but just curious if others have done the swap and what have they seen different with their boat in performance and economy?
Im sure the ls motors would use half the fuel, but will the boat be a total dog and not have enough ass behind it to get it up and going.
Any insight would be great.
Thanks
Tony
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Old 10-27-2018, 01:17 PM
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I have nothing of value to add but do think that would be a killer project that I’d love to see the results on.

On a side note since you deal with these small blocks in cars is can the stock LC9 handle any boost good for towing in my Z71?

Whats your plan for outdrives? Sounds like you’re aiming well above what a Bravo can handle but a beefier drive may need more torque than what the small blocks can give?
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Old 10-27-2018, 01:45 PM
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those little 5.3's love boost...are you thinking of using one of the lsa take offs and adapting to the cathedral heads? that combo is very common with trucks, those blowers make a ton of instant torque right off idle.
Keep the boost like 9 or 10lbs, good tune and it will make reliable power. Only issue really is the vvt and dod with those motors, also with the flex fuel setup your injectors should be good enough to cover the bump in power too.
here is some pics of a 81 camaro we are installing the lsa on a ls3 with truck accessories, we utilized this bracket by lsx innovations, very simple and great price.
oops, cant post pics till i have 10 posts

Tony
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Old 10-27-2018, 02:15 PM
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I’ve never heard of using an Lsa take off (I’m just helping you get to ten post here) Is it fairly simple to adapt?
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Old 10-27-2018, 05:46 PM
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A guy posted on that Facebook thing that he swapped his 454 for an LS and gained 5mph on a 21’ open bow. If you were talking 33’+ than I’d say that wouldn’t play out well but I’d think a 30’ would welcome the diet.
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Old 10-27-2018, 05:58 PM
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I'm just curious of the 454 CI 680 ish HP recipe?
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Old 10-27-2018, 07:35 PM
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combo would be basically 11:1, hyd roller cam (thinking something in the 234/242ish), aftermarket alum heads (ported), leaning towards dual plane intake with hp950 carb and dry exhaust should do it
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Old 10-27-2018, 08:09 PM
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You should just stick with your BBC's and stroke them 489-496 and with the right components and CR (so you don't detonate it to death) and aim for a little more realistic power. 600 + or -. Are your current engines 330's or 365 mags. (2 or 4 bolt mains). And lastly forget about fuel consumption.
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Old 10-27-2018, 09:03 PM
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yeah with the dual plane intake option i would say closer to mid 6's on them maybe alittle more,,,but yeah i'm not liking the fuel usage...with reworking the chambers i can make them detonation friendly.
i want to say these were 420's
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Old 10-27-2018, 09:17 PM
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Sucken gas and haulin azz!
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