I have a '99 Ram Slt with a 408 stroker. This is my first TBI stroker and I am running into some problems. First off the heads are stock, the intake is stock and I have added a Fastman 52mm TB (got it on Ebay dirt cheap). The cam is a MP purple Roller #5007551. This is one step up from the R/T cam. PCM is stock but I have added a Jet chip #90002S. I have installed a low temp thermostat and I am having a problem with light detonation under W.O.T. I am using premium fuel. I was wondering if anybody could tell me if the stock injectors may be causing this problem due to fuel starvation. I read somewhere that I should be running 28-30 lb. injectors. Can anyone verify any of this info for me. If you have a 408 Magnum I would like to hear from you.[&:]

 

It sounds like your injectors could be a problem, you should contact Marty at www.krcperformance.com, hell be able to help you with all your problems.