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LM7 question?

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Old 04-13-2012, 05:30 PM
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im getting some stock heads ported and polished and milled 30-thousands. my question is i already have harden push rods with my cam, but do i need to get a different length?
Old 04-13-2012, 05:49 PM
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You're milling 5.3 heads .030"? That's a lot, maybe too much.
Old 04-13-2012, 05:52 PM
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ya thats what i was told nehow? im having a buddie of mine's buddie do it? ive never done heads thats what they said that they would do and should bump the compression like 10-1?
Old 04-13-2012, 07:02 PM
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be sure to check piston to valves
may have to run a little thicker gasket

and yes definitly check your pushrod length
Old 04-13-2012, 07:31 PM
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im 99.9 percent sure im running 7.4 pushrods, and from were to were do i need to measure? i been doing some looking around and have seen that people are running heads .030-.045 using 7.4 rods and stock ls1 gaskets? if im wrong please feel free to correct me thanks for the help
Old 04-13-2012, 09:03 PM
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Are they running the 5.3 heads or LS2/LS6 heads? The 243 heads definitely can take .030" mil. I'm not so sure about the 5.3 heads, that would be about 56cc combustion chambers. Dunno, that sounds like you could run into some PTV issues, depending on the cam you use.

As for pushrod length, you need to use a pushrod checker.
Old 04-13-2012, 09:30 PM
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whats ptv? and im currently running a tr 220 cam .551 lift on 114 lsa, with 7.4" push rods. im trying to see what the casting number is on the heads, and ill get back to you guys, i know the guy was running these spec heads on his truck
Old 04-13-2012, 10:21 PM
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PTV = piston to valve
Old 04-13-2012, 10:28 PM
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o got ya, well i talked to my buddie he said there 706 or 862 heads, they were tested the other day, ported and polished for .030 mill? idk im just going off of what they said. i know the guy knows his stuff im just not sure on push rods and gaskets?
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