Hello I am new to this forum, from what I can tell you all can probably help me with this problem. I have a chevy 350 it is a fresh rebuild less that 3hrs of running. It has a holley intake dual plain, holley projection 950tdi,mallery distributer,flat top pistons, steal roller rockers(1.5) headers and single exahust. The problem is the timing light says that the timing is 48degrees advanced at idle (850rpm) it does not pop through the exahust then but if you rev to approx 2000- 3500 it will back fire and pop through the exauhast. I have not really tried to road test for fear that the engine would incurre damage from being advance so much. the commpression is approximatly 11to1. I am running 93 octain gas.
I have just recently tore it down to the timing chain and checked it and it is set just per the instructions in otherareas on the forum. I am really confused and if I spend much more time in the shop my wife and kids are going to find a new dad. Please help if you can.

MOJEEPER