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LQ4 build help

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Old Jul 11, 2012 | 11:52 PM
  #1  
1999Z28's Avatar
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Default LQ4 build help

I'm putting some ported 243 heads/ls6 springs and a cam on my 04 2500 soon.

I'm assuming stock length push rods will work since the heads won't milled or anything. Maybe someone knows

Also I'm hoping stock 02 fbody 28 lb/hr injectors will be large enough. I want to upgrade the stock 24.5 lb ones.

I'll be using this cam

http://www.lunatipower.com/Product.aspx?id=2023&gid=288

Any input would be great. My heads got a mild port/valve job. I haven't gotten the full flow numbers, just heard they flowed
294 @ .575 intake
233 @ .575 exhaust
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Old Jul 12, 2012 | 03:22 AM
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Originally Posted by 1999Z28
I'm putting some ported 243 heads/ls6 springs and a cam on my 04 2500 soon.

I'm assuming stock length push rods will work since the heads won't milled or anything. Maybe someone knows

Also I'm hoping stock 02 fbody 28 lb/hr injectors will be large enough. I want to upgrade the stock 24.5 lb ones.

I'll be using this cam

http://www.lunatipower.com/Product.aspx?id=2023&gid=288

Any input would be great. My heads got a mild port/valve job. I haven't gotten the full flow numbers, just heard they flowed
294 @ .575 intake
233 @ .575 exhaust
LS6 springs are too weak to handle that cam grind.
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Old Jul 12, 2012 | 03:54 AM
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go with PAC , proven springs.
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Old Jul 12, 2012 | 08:28 AM
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The LS6 springs would be marginal, I would not want to rev above about 6k rpm. Even 28# injectors might be borderline. Have your tuner log the injector duty cycle, you really don't want to go much over 80%.
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