4.3 chokes and dies then no spark !

Ok guys im am really stumped . so i just had my 4.3 merc. rebuilt and i droped it in about 3 weeks ago . hooked all the wires up like just like the diagram say to . i double checked everything then hit the key fired right up set timing . let her run on muffs for probly 2 hours then shut it down . started it up the next day then rechecked the timing . gave her 2 quick revs to about 2500rpms . then it just started choking and died . hit the key nothing . well rebuilt the carb and then checked for spark nothing ! went threw the steps changed out the coil nothing ! so i orderd a used thunderbolt iv ignition and hit the key fired right up . rand it for a while on muffs then put it in the water ran awesome for about 45 min then was at about 3000 rpm. and just started choking again and died then no fire what so ever . exactly the same as the first time . any ideas ? thanks for any advice !!

Re: 4.3 chokes and dies then no spark !

I would check the Thunderbolt again, if its dead again you may have a wiring problem that is killing it.