ignition knock

[cali-life]

Im in need of help bad can figure this out.
rewire my 68 Firebird front to back installed a few new parts to my 402 BBC new distributor msd street fighter i believe and new rebuild carb holley 650 double pumper.
After that when i started the car for the first time bad a really bad ingition dump knock from engine and back fire when revving high and it wont go away. only goes away when bass t timing is at around 55 deg ive heard thats to high. im trying to drive this car again but i dont want to block something up i also check for vacuum leaks did not find any
any help or someone run into something like this before?