HARDENED exhaust valve seats

HARDENED exhaust valve seats are they really needed or just hype.(351c 4v closed chamber).- unleaded pump gas .
also what is a good /normal price for them installed? one shop told me $40 per seat
i`m just trying to see where i stand. thanx

need for unleaded pump gas.

$40 per is too much. the last clevland heads I had done was a total recondition with the valve seats, valves, springs, all the hardware, and machining(not race oriented) for about $500. This was for a restore.

HOOK wrote:HARDENED exhaust valve seats are they really needed or just hype.(351c 4v closed chamber).- unleaded pump gas .
also what is a good /normal price for them installed? one shop told me $40 per seat
i`m just trying to see where i stand. thanx

I know the economy is not ideal but 40 per seat
I would really be running the otherway.
I did cheat the system though, went down to autozone and traded in open chamber 2v's for remanufactured closed chamber 4v's 375 total

If you run without the hardened seats you will damage the heads, or even destroy them. Leaded race gas is the only alternative, unless you want to try the "lead substitute" in a can at every tank full, and I have not heard of anybody doing that with success. You are way better off putting in the hardened seats, and it should cost around $500. to have you heads completely redone. Thats the going price out here in CA.

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$40.00 per seat installed is excessive. $30.00 is more typical.

We have been selling ported iron heads for limited street use for 7 years and have yet to have a set come back with sunkin exhaust seats... The iron in ford heads is much better than the stuff gm utilised in the 70's. That being said if i am preparing a pair of heads for a truck or motorhome application they will get hard seats with a .080" wide 45* angle because of high exhaust temps and exclusive street miles. The average street strip guy that sees limited street miles does not need hard seats in most cases. High spring pressures / high RPM with solid roller cams might be an exception.

The only ford heads i see with sunkin seats are the truck D3's that do heavy duty towing and even that is somewhat rare as the seats are induction hardened excepting the early and mid 70's modles which still used regular leaded fuel.

One thing that the machinists need to know about hardened seats in the bbf and cleveland heads is that the typical recommended seat has a 1.5" ID which is a bit big for proper flow and port geometry. I prefer to use the 1 7/16 id seats then size the throat id to match the valve size used...