If your fuel filter is still full then it's probably easiest to just keep on cranking the engine over until it does fire up. This will likely take several attempts, don't just hold it cranking continuously, give the starter motor a rest every 5 seconds or so. it'll fire up eventually then leave it idling for a few minutes which will give you a chance to get back around the engine and inspect for any leaks. It may splut or cut out when you open the throttle until all the air has passed through.
When I did this on my 270 I primed the fuel pipe with fuel using an oil can prior to connecting it up. If you don't you can end up cranking the engine for ages even though it's meant to be self-bleeding.