Bringing A Classic LS6 454 Back To Factory Specs

https://www.enginela...-factory-specs/

The first models of the 454 are rare, and the LS6 454 is even rarer. Still, the unicorn of these engines is the Winters “Snowflake” aluminum heads and corresponding serial numbers. Only sold on 188 Corvettes in 1971, these heads reigned supreme in making horsepower with their rectangular intake ports, round exhaust ports, and open-chamber design.

I'm sure some people thought it would make more than that. 

Running that hydraulic cam and a lower static comp. rato probably had an affect, but then it was a break-in run and the way they wrote. they acted like it was fragile.  

I have big block with Brodix heads which use the same "porcupine" compund valve angles as the head above.

It works but watching the rockers etc as you turn it over I am never sure why. 

The pushrods have to be restrained by the slotted guides which whilst they don't always touch the pushrod certainly leave a slight rubbing mark on the pushrod.

As the pushrod comes up it causes the rocker arm to "wipe" across the valve stem head to reconcile all the conflicting arcs. My rockers have roller tips and I wonder if the rollers are slight slightly curved  to help the wiping motion.

The things can run at 6,500 rpm as they did in CanAm days.

The latest GM BBC engines are 632 cubic inches , yes nearly 80 CI per cylinder, but have new symmetrical heads so the famous staggered intake ram stacks of CamAm fame are no longer needed.

They give 1,000 bhp out od the crate!

One common method the Detroit automakers used in the muscle car era to underrate engines (for insurance and other purposes) was to quote peak horsepower at a lower rpm than the engine could actually run. 

For example, the LS6 above was originally rated at 450 hp at 5600 rpm, but it was easily capable of 6000+ rpm, as this dyno report shows.