lets gets some info on this as Argess mentioned...how was it running before the timing gear set and the Dizzy Replacement ?

If it was back firing then ? you might have had a burnt exhaust valve, and if it was sneezing out the carb..that would indicate a bad intake valve or timing being advanced to far, Or by slack in the chain and jumoing a tooth..
Your either going to get enough fuel to stay running at idle or not run at all...Or running and stalling but NO back fire !

As mentioned Bring #1 up on TDC..you can check that by pulling #1 plug out and putting your finger over the plug hole..and when it blows your finger off..its close to TDC... At that point find your #1 plug wire at the Dizzy and mark it with chalk on the dizzy so you remember where it is..Pull the dizzy cap and see if the rotor is pointing at the terminal on the cap... If not.. Pull the distributor and move it until it points to that terminal..

With the angle at which the dizzy gears are cut..It will look like your going to be off a touch lining it up.. Just looking at it buy sight and dropping the Distributor in..Take it a tooth off and watch it when you drop it back in...and you'll see that when the distributor gear mesh's with the cam gear..it will slide into place.. And damn sure dont drop the Oil pump shaft in the pan !!

Have fun !!