I think that strip kit, or whatever they call it might be needed. I had a stumble that was hot or cold, pump shot made no difference, so I made a temporary fix by stretching the springs under both metering rod pistons by just shy of 1/8". That's not the correct fix but it's been there a year now and it drives 99 percent better. It's a vacuum signal thing, 500" 400 block with that 528" solid mopar cam.