Do these heads have hardened seats?

[Trevor B]

According to the serial numbers:
The block is a 1979 318 ( 4179730). It is 0.030 over on a 25 year-ago rebuild then was pulled and sat for a long while.
Intake, although it's coming off, is 1967-69 2 barrel (2468960-2)
Heads are 1968-74 (2843675)

Is there a way to tell if the heads have hardened exhaust seats?
The plan was to do some home head porting, possibly put in 1.60 exhaust valves and get a valve job, put in a 4 bbl manifold and carb, and put in a cam.

 

[RustyRatRod]

Those show up as 68-74 so I am gonna say "probably not".

 

[pishta]

'Seats' were not originally a separate piece so the head area where the valve seated was induction hardened a few hundreds deep. You could get them cut and add press in hardened seats at a machine shop. Good time to get 'em bigger if thats what you think you need.

 

[nm9stheham]

The hardening of the seats would have started in '71 or '72 to be ready for no-lead gas in '73 (and maybe in '72 in California). So it could be either on your 675 heads.

 

[moper]

Mopar hardened the iron around the exhaust seat with heat. "Induction hardening". They started around '72, so you really have to know when the heads you have were actually made rather than the production run they had. Also, the induction hardening is not very deep. So if they had a valve job, chances are it went through the factory hardening layer. When in doubt - have new seats installed. But - you might save some pain and simply by EQ Magnum heads with the LA intake pattern. You can buy stock Magnum rockers, and have a much better flowing set of closed chamber heads for less than the cost of the working of a set of original 318 heads.

 

[Marcohotrod]

check the casting date.

 

[Trevor B]

Thanks - I've come up with a much better plan. Gonna slap this engine back together and ditch it for a 360 instead!