Good stuff!
In my 1981 C20, it is a low mileage truck, I'm the third owner. With it being low mileage I wasn't concerned with replacing the heads. I installed vortec heads and a spreadbore vortec intake. That improved the power, while using the stock single exhaust and exhaust manifolds. Vortec are known for great flow at lower rpms. About a year later I removed the engine to re-seal everything. I figured while it was out, I would swap in the 300hp/327 cam I had, and that really increased the power. That truck will pull hills much easier than it did before, and using much less pedal to do it. The 4.10 gears help there, too, I'm sure. I like the single exhaust for the scavenging effect, and this truck is the first one I had with single exhaust on a v8. I've never been disappointed with how it performed, even in stock form, but I like the improved performance the vortec setup made. Better exhaust would improve it more, but for visual emissions testing criteria, I plan to leave it alone as it passes the sniffer and visual with flying colors.
My 4.0 Jeep, it runs great as-is, so it will be left alone.
The head for the 292 will get 0.030 shaved off, has 1.94/1.60 valves. Exhaust will be freer-flowing than stock, while having scavenging. Ignition will be HEI. The sweet spot for this engine is 2,200 rpms. We'll see if it happens.
I've heard when porting, not to reshape the ports, just smooth them out some, knocking off the cast-flash, and gasket match for smoother less restricted air flow between the intake manifold/head and head/exhaust manifold(s).
