34 is a decent place to start.
Once the timing is in the realm of right...you can make sure the carburetors throttle plates are opened only to expose the transfer slot about as much as .020 ish ..or to make the shape of a square...and then play with the idle mix screws setting them an even amount of turns out..whatever that may be.. 1/2-2 1/2 turns out 'depending if it's a 4 corner idle holley or 2...or if it's a carter design.
If it wont idle after that... you have a carb issue or worse a bad tq convertor or ...the wrong one 'too tight'.
What cam? Stock?