Best Convertor for 340

Running a dual pane LD340 intake, cannot say what cam is in it, I guess my next step would be to see if there are any numbers on the front of the cam to identify it. Will be running g60 on back or widest I can go without modifying the springs. Will run 15" all around. The engine is suppose to be stock except for the intake and the 670 holley. Any suggestions?