heres the deal. sbc350 .060+, 12:1,vortech heads,hurricane intake,solid cam .540 lift think its .240 at 50,650 holley dbp. Now everythings great until about 5100 to 5200 then it smacks a rev limit.i thought mabye fuel pressure loss, not the case.Then i thought mabye spark,not the case.Ill go and do a pass get out check the plug and the timing mark is down next to the first thread,this was at thirty degrees timing.so i back down to 28dg,no change.I then thought mabye it need to be jetted up a little in the rear,so i go from 76 to 78,no change no matter the timing.The thing i was thinking is that i have stock manifolds on the car right now while headers are being made.What are the odds that this is the problem,hense not allowing it to breath out fast enough causing it to run lean