The dual plug heads fit ALL Novarossi .21 engines and I won't say about the performance gain BUT for competition to get beside one of my drag cars or street cars
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Nitrohead, man I have also been tuning, tuning and tuning on my CD3 chassis and now can make the stock style Jaco 1/10th scale foam tires hook and work with all the .21 power being thrown at them[X(]. I gotta get some more vids of the cars to show you how well those regular tires now wrok but it is ALL in the chassis set up, springs and shock oils that did it.