Hardened seats?

[harvenator]

I'm rebuilding a '65 273 and am having the heads redone with new valves and springs. I've been talking with the guy who will do the heads and we've been trying to figure out if it pays to put hardened seats in the exhausts or not. I've heard that the Mopar heads had a high nickel content and really don't need them. I'm running a solid lifter cam and don't need to be constantly readjusting lifters because the valve is sinking into the head.
Is there anyone out there who has had an experience with and without the hardened seats in the early LA's? I intend to drive this thing a lot once it's done.
I'm sure this will stir some controversy.

 

[65 Dartman]

Whenever I have a set of heads (or a head for a slant) done, I have hardened seats put in just for peace of mind.

 

[moper]

No contraversy. If you want it to last, replace the seats with hardened ones. If you dont care, dont. You may not need them. But you wont know until it's all together and with the seats, you're definately fine.

 

[ramrod]

for the long run, its just best to put harden valve seats, i already had a problem with a ford once, 69 mustang with an orginal 302, ran it for 3years as a daily driver and took it to the tracks and i started having problems, checked compression and 2 cylinders had no compression, took it apart and found out the exhaust valves on the head that served those 2 cylinders was sunk in the head, blew my mind but didnt know about the leaded fuel at the time which cushions the valve seats. but anyways like i said just go with harden valve seats!

 

[Petzschler]

just looked at my set of J-heads (35+ years old and over 130k on them.) damned if i can see/measure any sunked valves.
These heads where ran on 10% ethanol for most of its life so i'm guessing that had something to do with it.

 

[fishy68]

Ive seen sunken valves due to no hardened seats and as you stated

I'm running a solid lifter cam and don't need to be constantly readjusting lifters because the valve is sinking into the head

That alone should tell you that you need hardened seats.

 

[Dartnut]

It's good insurance to put 'em in now.... how much would it cost a couple of years trom now to install them if you're wrong?

 

[cudamark]

Unless this is going to be a show original resto, do yourself a big favor and put the original 315 casting heads and intake on a shelf in your garage and use a later setup. The 315 casting has crack problems (inside and out), the flame travel is poor, and with today's fuel, it usually pings unless you're going to run race fuel or octane booster all the time. If you need the stock look, use the 675 casting off a '72-4 318. It will have the same port sizes and has induction hardened seats from the factory. With the open chambers you can use pump regular gasoline. The '66-7 273 intake looks the same as yours (even though the casting number is different) and has the same hood clearence. Intake gasket sets are easier to find and the castings are easier to find and more reliable.
Good Luck, Mark

 

[harvenator]

Actually the heads looked real good. I had new sleeves and seats installed along with new valves and springs. Can't wait to crank this baby up.