It's hard to give advice, without actually hearing it run. Also was this 347 a stroker kit, that you built or was it a crate motor? Where the motor came from would also help, and what type of supercharger and who put it in? If you can take a video of the entire assembly while running, need to know you fuel management system. Do you see where I'm going with this, it's very hard to troubleshoot a problem on what someone is telling you without listening to the engine running. Or even see how it runs, under load take a video and post it, Mike. SCT Tuner.:bigthumbsup