Fuel pump push rod problem

[sams442]

How about some help guys. I have to run an electric fuel pump on my 82 truck because two different times my push rod has mushroomed on the end that goes against the camshaft. The end flares or mushrooms so bad It won't slide out! Had to pull the cam and grind the shaft down on the end so it would slide out. Gave me a chance to put a 268 comp cam in any way! Also installed new push rod and fuel pump. Everything was fine for about two weeks when all of a sudden no fuel pressure. had to go back to electric. Any help would be great. Thanks