Do 5.3 706 heads need new seats for 2.00" valves?
12-21-2011, 04:28 PM
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Do 5.3 706 heads need new seats for 2.00" valves? Have a set of 706 heads and a set of perimeter bolt 5.7 heads. I was wanting to have the 706's ported and upgraded to 2.00" valves. Does the machine shop need to put in new seats or cut the current ones?
Jason
Jason
12-21-2011, 07:04 PM
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Normally anytime You increase valve size the appropriate seats need to be installed . I decided to experiment with My 706's and while I was porting them I ground the inner diameter of the seats .050" larger so in effect I've increased My valves to 1.94" and 1.60" so I'm gonna run engine with a 2 row 1" wide row radiator and I probably should use a 180 or even a 165deg t-stat so hopefully I won't have any seats crack . But if I do I've got a good pair of 862's that I can put on . So when I get-er runnin finally I'll update whether or not I have any problems with the thinner 1's .
12-22-2011, 01:19 PM
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So he must have ground the inner diameter of the seats to a larger size . That would leave the intakes extremely thin . Good to know so I should'nt have any probs with mine . If You don't need new valves then just make the inner diameter larger and it will work the same as putting larger valves/seats in . The seats are the restriction here Actually with increasing the inner diam of the seats and leaving the existing valves flow would be better at the valves than larger valves with the same inner diam seats .
12-22-2011, 04:57 PM
#6
No, you do not need a different seat to run the LS1 2.00" intake valve in the 5.3L heads. Just setup your valve job, blend the bowl appropriately, and let her rock.
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COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
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POWERBOND - ASP - AND MORE!
12-22-2011, 05:40 PM
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I have a local guy that does great work for little $ for my uncle. $150 balance and $350-$450 to mill, step up valve size and port heads.
We'll see how they work out!
Jason
