Hardened valve seats?

[STL84Calais]

Ok, as y'all know, I'm building a 1970 455 Olds. I have the E heads (big valves), I've been told that for some reason, on Olds motors, you can run the soft valve seats with pump gas and it won't really harm them. But, I've always been told that if you run soft seats with pump gas you will tear the piss outta' them. So, general opinion; should I spend the money to have the heads redone with hard seats, or should I just leave them be with a port & polish?

 

[RegalBegal]

I'm not the Olds person. I know on Buick, you don't need hardened seats because of the nickle content in the cast iron. It's like the whole head is hardened. Since Olds was the next step up from Buick, I would assume their engines were the same. Chevys need the hardened seats because their heads/blocks have almost no nickle content. And of course, when the performance community talks tech, they almost always mean Chevy.

 

[joe_padavano]

Ok, as y'all know, I'm building a 1970 455 Olds. I have the E heads (big valves), I've been told that for some reason, on Olds motors, you can run the soft valve seats with pump gas and it won't really harm them. But, I've always been told that if you run soft seats with pump gas you will tear the piss outta' them. So, general opinion; should I spend the money to have the heads redone with hard seats, or should I just leave them be with a port & polish?

It depends on how many miles and how hard you plan to drive. I had non-hardened heads in my 70 and used it as a daily driver for years. The only thing that MAY happen is that you'll need to do another valve job in 80,000 miles instead of 100,000 miles.

If you do plan to have hardened seats installed, be sure to use the Olds-specific seats. They are shorter than the generic Chevy seats that most machine shops use. Cutting the heads for the taller seats may cause you to strike water.