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427 build help needed 4 newb

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Old Jun 30, 2009 | 06:18 AM
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Default 427 build help needed 4 newb

hi guys, I've perused the forum many times as a visitor but am only now a member...hello one and all.

to my question...

I recently bought an LSX based 427 built for boost with 8.5 static. It has been run but hasn't done any real work, less than 1000 miles or so.
It currently has a pair of AFR large bore 225's (which will be for sale) on it but I'm looking to up the game and make some more grunt, it was punching 800rwhp with the current twin turbo set-up. I have a pair of GT45's now and want to double that figure.

Can you bolt 12deg LS7 heads to an LSX with 8.5 CR wouthout fear of valve clearance issues? I want to go to the Bill Mitchell prepped World Products with a large custom turbo cam with .630 odd lift. I know the valve-train will need to be upgraded to suit. I just don't want to spend 3k on a set of heads that won't work without a piston swap. I know ideally it will need to be dummied up but if it is within the realms of possibility and has been done I'll give it a shot.
Thanks in advance.
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Old Jun 30, 2009 | 09:33 AM
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actully with a 12 degree head the valve will have more clearance than the normal 15 degree. the valve actuall sits flatter towards the top of the piston. buy from the sounds of it this engine aready has pistons with a preaty mean dish to them. ; )
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Old Jun 30, 2009 | 10:42 AM
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thanks for the reply novaflash.

that's what I was thinking..as far as the dished piston and the valve angle goes, just wasn't sure how the 2.2" intake valves would go at full lift?

worth the risk and just buying them do you think?
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Old Jun 30, 2009 | 11:07 AM
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Remember also that the valve is no where near the piston at full lift since the piston is at the bottom of the stroke. You need to check your valve events to see where the valve is when the piston is near the top of the stroke.
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Old Jun 30, 2009 | 07:17 PM
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yeah your spot on 1cam...it's amazing how as soon as you start looking at the project in its entirity you begin to forget the basics. I think there's a bit of scaremongering and over cautiousness to avoid blame when the crap hits it.. from alot of engine builders...can't blame them really, better to be safe than sorry.
I've arranged a set of heads for dummy-up and will let you know how it goes. bring it on!
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