I seriously doubt MSD ignitions fail to work properly over 3000 rpm, theres too many of them being used on serious go-fast cars for that. But rather than take my , or anyone elses word for it, just go to the MSD site and check out what they have for your 360, 440, 392 etc etc etc and see for yourself. Most , if not all, of the aftermarket parts manufacturers have websites with technical help, so why take the word of some droid from Summit, PAW, Jegs, etc.....knowledge is power and its usually no more expensive than the time it takes to acquire it! Mikey 62 Crown Coupe p.s The reason I didnt post the MSD website is, well...if a person cant even FIND them on the internet then maybe they shouldnt :)