No start 340

I agree with all above.
1. I would do a compression test first. One time I saw a 440 with solid lifters and the valves were adjusted so poorly that compression was practically zero on all cylinders. No compression, no running engine.
2. Make SURE the rotor in the distributor is pointing to the #1 spark plug tower when the engine is at TDC in #1. That means you have to be absolutely sure you are on true TDC. Remember that the timing mark tab will hit the "0" line in the balancer for #1 when the piston is at true TDC and again when the piston is at the top for the exhaust stroke. To find true TDC, turn the motor over a little at a time. When you start feeling pressure coming out of the spark plug hole, the piston is on its way up for the compression stroke. That means that the next time the timing tab hits the "0" mark on the balancer (and it will be REALLY soon), #1 is at TDC.
3. Make sure you have spark.
If you have compression, if you ensure the distributor is installed properly and if you have spark and fuel, it will run.