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how much for this head work on a 350 manum?

Old 01-14-2004, 03:09 PM
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Default how much for this head work on a 350 manum?

I just bought dennis moore's book and I love it!! As some of you know I am looking for a little more horsepower for my formula 206!! I am going to do some head work and possibly a cam change for this year!! now dennis' book states that if I remove my heads and machine them for larger 2.02" diameter intake valves and larger 1.60" exhaust valves, then port the valve pocket throats. that Ill see at least 20 horsepower with the stock camshaft!! What will a machine shop charge for this and to put the new valves in?? Also any know of any other cheap head tricks!!
oh yeah the motor is a 1989 350 magnum!
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Old 01-14-2004, 05:00 PM
Join Date: Jan 2004
Location: Long Island NY.
My Boats: 1988 Fourwinns Liberator
Posts: 450

Before you do anything, pull the heads, and check the water jackets. If it's raw water cooled the jackets might be so rottted that it won't pay to invest any kind of money in those heads. My heads(1988) were rotted around the water passages at the gasket surface opening the holes to the point that they were impinging on the combustion ring. Time for new heads. Cutting a 30 degree back cut on the valve face helps partial lift flow. It's good for a few CFM. Check out Good info on head porting for SBC.
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Old 01-14-2004, 07:03 PM
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My Boats: Formula
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Unless already changed to Vortec, your heads on that 89 Magnum will be the 'light-cast' head, and really aren't worth spending any money on. A good machinist will more than likely find a crack or two in them, and they do not come through surfacing well, if at all.
You are much better off putting your $$ into a set of Vortecs and having them machined for larger valves and springs, or buying the World Products heads that are already completed and ready to bolt on.
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