I was thinking about picking one up at Jegs to replace my open 1" spacer. Has anyone tested one - they state 10-50HP gain ...but we all know how that goes. http://www.jegs.com/i/JEGS/555/15420/10002/-1?parentProductId=751906

Do these card spacers make a difference or are they like the Splitfire plugs and the magic Tornado?

33 Plymouth Roadster - 383 - 5.90 1/8th 9.58 1/4
68 Dart - 340
66 Belvedere - 400

Windy Hollow Garage - https://www.youtube.com/@windyhollowgarage