Technical Dual stromberg on 8BA help

Hey everyone I could use some wisdom here. I have an 8BA with an isky 400jr cam, thickstun pm7 intake and two fully rebuilt stromberg 97’s and the new stromberg e fire 8BA distributor set to 10° timing. Plugs are b-6 jets are 43’s with 67 power valves at 3000ft elevation. Not running progressive linkage. Fuel pressure is set to 2.5lbs

Issue is new to me as it didn’t do it before. Engine fires and idles perfect however if I attempt to rev it up the engine wants to die and falls flat on its face and smokes black. If I choke one of the carbs 1/2-3/4 and try to rev it up it responds great and revs right up. Any help or tips would be greatly appreciated.

 

Are you using both accelerator pumps? When I ran 3 stromberg 97's on a flathead only ran 1 accelerator pump

 

If choking it makes it run better, it is running lean. If it ran good to start with, I'm guessing dirt in one or both carburetors.

 

I am running both.

 

I'm thinking you need a selection of jets and a jet wrench. I believe the stock jets were 45 main and the pv was a 65.
I would think that you would want to start with the stock jets and then change from there

 

Ran great initially for quite some time and yah now this issue has come up. I opened up the rear carb today and made sure everything was clean and working. I’ll check the front carb tonight

 

Get rid of the "E-Fire". Replace it with something else, (an old Mallory dual point, a converted SBC, or even a "Load-A-Matic") and see what happens.

 

Did it pop back through the carbs at any point? The power valves are to help with tip over from idle running. If you pop a power valve it would have a problem kind of like you are explaining. Also power valves that are not properly sized will cause a problem as well.

Sizing a power valve is something that you kind of feel for. You start out by measuring idle vacuum and dividing that in half. For example, if you are holding 14" of vacuum you would start with a #7 power valve. Now it is not an exact science, in this instance a #7 is a starting place, you may got up or down .5 to 1 on the power valve number from there.

 

I removed one of the carbs confirmed that power valve is good. Going to pull the other and check it. The old school speed shop guy who sold the cam helped spec the carbs.