As a suggestion, see if the fella with the rockers will let you run 8 on the exhaust and buy them if the car runs quicker in A-B testing. If they don’t, return them to him. I’d be interested to know the results.
As to if this would work, I think it might. But that all depends on what you have for a cam right now. Reasoning? Replace the headers with zoomies and you lose the wave and inertia scavenging the headers produced by way of the length of the pipes and the collectors. Your engine is now down on power, just as your testing proved. One way of getting some of that lost power back is to get rid of more exhaust gases quicker to help overcome the current lack of wave scavenging. If you replace a 1.5 arm with a 1.6 arm everything that happens on the valve side of the arm occurs quicker, or sooner. According to Dick Jones, Jones Cam Design, when he tested a cam with 268* duration @ 0.050” lift, he found the cam picked up another 2* duration with the addition of the 1.6 arm. At 0.200” lift it saw a 4* duration increase. So, maybe increasing the length of time, along with the additional lift, will better evacuate the cylinder by the time it gets close to TDC. Might work
I like your attitude…do not remove the zoomies!
