stroking a 6.0L
Thread Starter
Melting Slicks
Joined: Feb 2004
Posts: 2,435
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From: largo florida
stroking a 6.0L
What is the largest a 6.0L can be stroked before big money is need for clearancing and other problems arise? Is the 422 as safe as the 408? Any other comments are greatly appreciated.
Burning Brakes
Joined: Jul 2003
Posts: 867
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From: Houston TX
6.0 stroked
Maybe this will be helpfull.You can use these bore sizes 4.0, 4.030, and 4.060. You can use a stock crank or 4.0, 4.125, or 4.250. I have a 4.030 bore ( these leaves room for a rebuild) and a 4.250 crank. This gave me a 434 C.I. motor. I have had no issues in the motor and raced it for almost 2 years now. The 408 is a cheaper and more standard kit. You can spend more money on your heads. Good Luck Bill
Thread Starter
Melting Slicks
Joined: Feb 2004
Posts: 2,435
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From: largo florida
Is any special clearancing required when you start hitting the 2.125 and 2.250 crank sizes? If so, how much? Is is clearancing that I could do at home with a dremel or is it serious massaging that a machine shop would have to do? Thanks for the reply.
Melting Slicks
Joined: Oct 2002
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I would think you better take it to a machine shop there is some serious clearancing issues with even a 4" stroke much less the longer ones and then you have to custom grind on the pan to get it to fit as well--I wish I had stayed with a 4" stroke and gone with a 4.125 bore for a 427--if I downsize stroke to 4" I will have a 422 with my 4.1 bore--In your case I agree with the 4.03 bore leaving room for a rebuild and I would use a 4" stroke for a 408ci and have a good strudy high rev motor---I like Chris at ECS 434 he uses a 4" stroke and a 4.155 sleave in his alum block for a high rev big bore motor--this is pushing the envelope on the alum block as this is max sleave that will fit--your 408 by the way is plenty sturdy for a big shot or other forms of FI--
Premium Supporting Vendor
Joined: Dec 1999
Posts: 1,984
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From: Texas Speed TX
We typically sell 408 cid iron blocks (4x4.030) You can definately build bigger stroker, but alot of people feel like it shortens the expected life of the engine.. We recently did a 4.125 stroke setup & it worked very well though... A 4.125 stroke would make a stout 422 iron block 
Thread Starter
Melting Slicks
Joined: Feb 2004
Posts: 2,435
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From: largo florida
What are the differences between the LQ4 and LQ9? I heard the LQ4 heads are the same as the z06 heads except larger combustion chamber, is this true? Everything between genIII blocks is interchangable right, including cam and intake right? same bolt patterns? Are there any specific years or models that I should look for when looking for a 6.0L, what about the LQ4 and 9,is 1 better then the other? Is teh maf the same size as the ls1? Thank you for your help. It is hard to find good information on the 6L for some reason.
Thread Starter
Melting Slicks
Joined: Feb 2004
Posts: 2,435
Likes: 0
From: largo florida
How much clearancing is required to run the 4.125 stroke crank? Is the 422 a good block for FI or n20? Or is the 408 better for that? It seems that the internals for both the 408 and 422 are about the same price, is there any reason to go with the 408 instead of 422? Thank you for your help.
Melting Slicks
Joined: Oct 2002
Posts: 2,855
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To use a 4.125 stroke with the iron block and make a 422 would require a 4.1 bore and I don't think you can go past 4.06 with the iron block--a sleaved alum block however built for a 422 is what BoweryBill and Major Spray use in their big shot NOS cars--the 408 or 415 with the 4.06 bore make great Nos motors as well--
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