is this a new problem? what did you add? fuel pump push rod is probably not it. You could have a crack in the fuel line somewhere. most of the time the rubber piece from the sending unit to the tanks rots out and gets pin holes in it. Another thing is well here we go that 750eddy carb isn't going to give you all the ummph you need w/ a 440. Not saying it should die at 3800 rpm but if you are hamering it when it fails it could be a problem. If you can take it up slowly over 3800 say up ino the 5k range you can rule out electronics. So it would be fuel related.