Rebuilding a 65 273..I need some help.

Dmopower said

Ok. I started porting heads back in HS for my shop teacher who was a serious drag racer. I still have a nice hard seat grinder kit and an old Sioux valve grinding machine. I have been porting mostly BB Mopar heads. So I'm not new to porting, Not a pro either. But What is it about SS valves that prevents you from needing hardened seats? I have never heard of this.

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The stellite in stock exhaust valves will stick to cast iron or vice versa and act as a rotary file. The stainless steel does not seem to interact the same way. I suppose if you are running high rate springs and high lift cam it would be wise to have hard exhaust seats. I've found I almost always have to replace exhaust valves anyway, So that is what I have been doing. I only know enough to pocket port, match gaskets, cc chambers, unshroud intake valves, and grind valves. But that is plenty quick for an early A body for me. I always ran the best factory head and a 260-270 duration cam so it always worked well for me.