I had problems footbraking 3 circuit Dominators, and always converted them to 2 circuit. Not that big of a deal to do.

Things that come to mind are what rocker ratio, the lash amount and intensity of rhe cam, thickness of the rings, and the effect of the intake/adapter combo, and how much room for improvement there might be in those areas?
My first 440-1 build after porting the heads made over 840 hp with a similar cam but injected methanol. So i bet the things i mentioned may be holding it back from 850 hp.

I don't think it would require much work to bump this engine up to 850 hp but the owner didn't seem interested. The engine goes in a pickup that he drag races and he runs low 9's or high 8's and is happy with it.
From what I've seen over the years only about 5% of the customers are actually interested in finding more power after a dyno session. Most customers just want to get the engine home so they can put it in the car and get back to racing.

Did you guys do any work on that engine…….or was it just there for a dyno test?

Is it just me or are those dyno headers kind of small for 850-900 hp?

Did the owner at least have a few ignition timing settings tested?
The combination 4150 intake with carb adapter to 4500 may have limited top rpm power capability at 540 CID.
It would be interesting to see how the HP held up past peak. It might benefit from a higher shift point.

That is a good point. The 4150 to 4500 trick might work great on a 440 to 500 inch engine but not so great at 540 inches. I tested it on my 514 and the best intake for that engine was a 4500 intake. The Super Victor worked best for me. The 440-3 was okay, the 440-3x didn't make more power.

I think all runs were made at 35 degrees. I don't recall changing the timing on it.

It got rings and bearings, upgraded to a belt drive, fixed some issues. I think the short block was built by Indy originally but I might be wrong.

Most customers don't want to spend the extra dyno money. Also, there is zero reason to test stuff that doesn't fit the car. Why test carb spacers, if you don't have room for them? What good are dyno headers if they don't fit your chassis, other than they fit the dyno?

Just for comparison, had a Chevy 540 on the dyno today and it made 920 hp. Very similar engine to the 540 Mopar. This BBC is also all aluminum, similar compression, similar cam specs, single 4 bbl intake using the same 1050 dyno carb, both were wet sump with vacuum pump, both used dyno headers, both use Jesel belt drive, crank trigger with MSD, etc. The BBC heads are just that much better. This engine uses Brodix Big Brodie 3x heads. I think they are 365 cc with a big rectangular intake port. The intake port is so big it requires a special gasket and you have to buy the Brodix intake if want it to fit out of the box.

Those BB3 Heads are no joke! Brodix moved the valves around some (still 24°) to accommodate a larger valve without shrouding...they make power!

This is the first time I'd seen these heads. I figured the engine would make 850 hp since the compression wasn't that high and the cam was an off brand. But when we opened the throttle the engine started to howl and the needle spun on the HP gauge.

Funny thing about this engine is that the customer who brought it in bought it at the track from a guy who was pissed at poor performance. Guy was so mad he sold the engine for $10K at the track. Probably cost close to $40K to build an engine like this with all new parts.

Anyone know what a Ray Barton Hemi would cost? And what power they make

Years ago, there was a 'Cuda local to here that had a BBC in it, people gave the owner a hard time about it. At a car show a few of us were looking at it and some were not pleased with the swap, the guy's wife or his GF, not sure which, said something like, we wanted to go fast but had enough money to build a car or just build an engine.