Happy testing!!!

Looking forward to hearing the results.

I hope you find the time to test the ex manifolds....... I'm curious as to how much the power drops.

The last time I can recall doing that was on a stroker Cleveland Ford.
Manifold friendly cam....... Did all the tuning with the manifolds on, since that's how it was going in the car.
Still picked up like 40hp with the headers.

stuska dyno... cant get it to re-set .. computer is not working properly.. got to get that fixed now.... did put some heat in it though... cant get the video to load...out board springs are to light .. changing to blacks next....

Did you get good data? If not, I would suggest that you not change anything on the set up until you do. Especially if there is only a bog as the operator is loading the dyno before the pull starts.

Whenever I've dynoed a 6bbl motor, when the secondaries open it's usually rather abrupt........ Even when they're working fine in the car.

I install a small bolt with flat washers and a locknut in the throttle return slot on the center carb. to manually force the outboard carbs. to start opening sooner at WOT

"Bog of the century". I tried that back in the 80's and my car fell flat on it's face instantly

My motor was a 511 C.I. low compression pump gas 400 block originally in a 1971 Duster with Hooker fender well headers and three inch exhaust all the way back to the rear bumper, I later swapped the crank from 4.25 to 4.300 stroke to raise the compression ratio from 9.25 to 1 to 10.30 to 1 after removing the iron 906 heads to put the Eddy RPM CNC ported heads on. That motor in both compression ratio and C.I. would bog if I allowed the vacuum pods to open the outboards, not so with the helper bolt I did have to fine tune the carb. idle circuits, all three and the squirter size and stroke to eliminate that bog at the hit from WOT
It is doable with some work and effort

I built a 440/505 6bbl this year with a 440source kit, based on cab's advice.

installed lightweight springs in the vacuum pods, changed pump cam, and upgraded to the 50cc pump. I dont recall what jets, 60 something If I remember right.
Anyways, absolutely no bog, no hesitation. Heads were done by MarkZ( a member here)until funds allow for some nice aftermarket heads. A tire fryer at any speed even on the highway with street tires for sure!

Sure.

If you put lighter springs in and you load the engine the outboards will fully open before the pull is initiated. In this scenario, all 6 bbls are fully open and flowing on the main and you get good clean data right from the start of the pull. But if you instead have the carbs swing from fully closed to full open in a few hundred rpm right at the start of the pull it likely won't be representative of anything meaningful.

I'm not suggesting that this is the only way, or necessary the right way, but is a good starting point for your testing and data collection.

Russ, I'm sure I usually start the pulls at a higher rpm than what you would prefer.
But as a result of the higher start rpm, the motor gets to see some rpm before the load starts being applied.
When the throttle gets opened far enough to create some signal for the secondaries, they just pop open.
This usually happens before you even get to wot, so on all the 6bbl testing I've done, the secondaries have always been wide open before the pull even starts.

Certainly the higher rpm start will make it happen even quicker. But even down in the toilet where I start, they basically do what you describe.

My first pull on my low deck 511 C.I. stroker pump gas six pak motor I had the dyno operator start at either 2000 or 2500 RPM (CRS) to 5000 RPM.
I have since learned that on almost all the engine dynos used today if you set the start RPM on the keyboard and then slowly advance the throttle to full open all of them are at WOT before you can hit any button on the key board to start the automated pulls
BTW, it took that first dyno operator several pulls to not bring the throttle back when the outboards carbs. would open and bog

I know it's coming, so there is sort of an automatic pause with my hand in the application of the throttle.
Bring the rpm up a bit, start feeding the throttle, pause briefly when the secondaries pop open, then push it open to WOT...... Let the rpm stabilize...... Start the pull.

Does the plan involve porting the Stealths?

A nice CNC job really wakes them up!

no. running the stock exhaust manifolds i don't think it will help.

It would help with the right cam, just depends on what you want power wise & drivability .

What an interesting assumption.

i don't want to assume anything so please any insight, advice, or recommendations i will take. thanks. just trying to get a stock appearing crisp running engine is the goal.

In my less educated opinion cnc heads will make more power than box stock ones manifolds or not.I would expect greater gains with headers but gains none the less.A split pattern cam may help as well.More knowledgeable folks will chime in.

get them ported !!!!!