GM-GMC: 92 chevy 4.3 wont start, vent tube, spark tester

Question
I recently bought this truck knowing it leaked gas.After replacing the tank,sending unit,pump, all the lines from the tank to the carb,the filler tube,the vent tube, the filter...basically everything from the gas cap to the carb is brand new I also replaced the coil,distributor,the pickup coil I have spark but I don't think I'm getting gas. the injectors were taken out and cleaned ...before it would run for about 20 min. then stall after pulling the distributor and changing the pick-up coil.Now it doesn't want to fire?What should I do???

Answer
The first thing to do is figure out why it won't start.  Is it a spark problem or a fuel problem.  Look down the throttle body while someone cranks the engine and see if fuel is spraying out of the injectors (assuming it is a tbi engine)  Also use a spark tester and test for spark.  If you have no spark, it would seem to me that something went wrong with the distributor/pick up coil installation. Retrace your steps and see if you can find where the problem is.  This is a difficult question considering the amount of work that has already been completed.
Hope this helps