X HEADS
No, strokers and aluminum heads are. Why else would you throw so much money at them.
I sortof agree;
my 367 is a fairly tame engine yet goes 93 in Eighth. Who needs to go any faster?
On the street;
If you are replacing pistons, High cylinder pressure is "free" power and economy.
With iron heads; about the highest CCP that you can run without detonation at WOT, is 165psi, and you will need to run 91 or better gas. That's cutting it pretty fine, and if you find your cam is too big, running a smaller one may increase the pressure into the detonation zone, which then might require internal engine modifications.
Whereas with alloy heads, 185psi is a common target , and in my case at least, supports WOT on 87E10. And if you set that engine up for hi-torque, you will not require an overdrive. But if you do install one, then you can decrease your cruise rpm and realize significantly better fuel economy than at some other lower pressure. The higher pressure is not by itself responsible for the fuel economy; rather, it is the lower cruise rpm that the higher pressure supports.
For example; I have found out that my hi-torque 367 pushing 185psi, would pull very well at 65=1600rpm, and got fabulous fuel-economy while doing it; rivaling any modern-era injected 4-cylinder Compact Utility Vehicle, and many sedans also. Yet that 223*cam easily went 106 in the Quarter.
Because of the pressure/economy thing, I'd have to be pretty broke to go back to iron heads. But if I would, it would Not be with a big hydraulic cam. I'll be trying a solid-lifter cam at say 170 psi, and attempting to tune that for 87E10............ cuz that's the kind of guy I am.
I did the math once as to how much money my Eddies might have saved me in hiway .gas savings. Because I was driving over 6000 miles every summer in those days, the break-even point, to worked iron heads, was only about two or three summers.
