Anyone Use 6.0L Heads on 4.8L to Lower the Compression Ratio?
07-24-2007, 09:38 PM
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Anyone Use 6.0L Heads on 4.8L to Lower the Compression Ratio?
Will the valves clear the narrower bore? Im thinking of supercharging my truck and thought itd be a easy way to lower the compression.
07-25-2007, 09:34 AM
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Yes they will work on a 4.8. There have been several guys use them on 5.3's and the 4.8 has the same bore diameter, but it's probable not necessary and it will hurt the out of boost performance, and the 4.8 needs all the out of boost help it can get. 4.8 are around 9.5 comp stock I believe and I have ran mine to 12 psi with meth injection. A few guys have ran them all the way to 18psi or so on race gas ALL STOCK 
07-25-2007, 05:23 PM
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Leave the stock heads on there.When you lower the compression on that small motor the off boost power sucks ***.Just run the high boost with meth. We've run 14lbs on pump on the 4.8 with no problems.
07-25-2007, 07:26 PM
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Originally Posted by Slowhawk
Leave the stock heads on there.When you lower the compression on that small motor the off boost power sucks ***.Just run the high boost with meth. We've run 14lbs on pump on the 4.8 with no problems.
Andrew
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07-26-2007, 12:45 PM
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I still think its worthwhile to change the heads. 25lbs of boost would be better. Anyone have any experience with the kenne-bell kits? Looks like it would make similar power as the mustang cobras
07-26-2007, 01:47 PM
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I wouldn't do it either. I was really close to doing this too, but I just wouldn't want to deal with the loss in non-boost power/tq. It would really turn the 4.8 to a dog down low while driving around. A better option would be LS1 heads. I don't think they'd drop your compression that much.
The stock 4.8 won't last long either pushing 25psi. If you're serious about high boost, then why worry about the SCR. At the boost levels you're talking race gas will be a necessity no matter what SCR you have.
The stock 4.8 won't last long either pushing 25psi. If you're serious about high boost, then why worry about the SCR. At the boost levels you're talking race gas will be a necessity no matter what SCR you have.