Ron, again not an expert but just some observations. That engine should idle when warmed up at about 900- 1000 max rpm when set in gear, I think 1200 is too high.. The RPM drop from neutral or park should be around 100 - 200 rpm so you still have timing and carb adjustments needed. If you have a stock torque converter that comes into play as well. What is the stall of your converter? You're getting lots of great advice from the others.