Inliners International Forums General Discussion Engines original 261

I know there are a lot of opinions on the hardened seats vs non hardened seats. I have done heads both ways over the years but decided to stop installing hardened seats. One of the reasons is when I had a very competent machine shop machine a very pristine 848 passenger car head, the machine shop hit a casting flaw (thin casting) where the seat was. We only discovered it after the motor was back together and running. These 261 heads have larger exhaust chambers (some of the 261 heads are 86 cc other are 95 cc) so the casting may even be thinner at the exhaust chamber with the 261 heads. I have not seen exhaust seat damage except on heads that had loads and loads and loads of miles on them. Further, I have a head that has never had leaded gas, no hardened seats, and i will represent that I used this motor hard for over two decades (including many shifts at the 5800 rpm range). When I took it apart this past year there was no evidence of the exhaust seat having been pounded by the exhaust valve. So my call, as of the last few years (and of course everyone will make their own call on this) is to not take a chance making a good head into a pile of scrap by hitting water. And for the record, the new 261 that I just built for the 57 is a 59 848 head, 1 5/8 small block chevy exhaust valve, 50-52 chevy powerglide 1 15/16 intake valves, no hardened seats. As much as I love driving the car, i simply will not live long enough to put 100k miles or better on the motor and do not expect to see any kind of damage. Just my thoughts, for what they are worth, lol.