340 with 35 degree at 600 idel and 200psi compression

I am lost. I redid my 340 with a 474 280280 mopar cam 40 over trw pistons dual plane intake and a 600 double pump holley heads are not ported but are 4 angle ,.500 stainless steel valves , heads shaved 10,000 my compression is 200 psi and my timing is 35 degree at 600 rpm. HELP I can't turn down the timing without the engine dieing is the 200 compression the problem? At idle 600 rpm the timing is 35 degree. Gears are right. Gil