vapor lock

[Guyz55]

I purchased a 55 stepside 3100 w a 350 in it in april of this year ....it has been running great ...I use it everyday as its a daily driver ....however there have been times when it will run great I park it and then it is real hard to keep running ..I am being told what I am experiencing is vapor lock ...I took it to my mechanic and he said he re routed a fuel line away from the block ....but that did not help .....does anyone have a ideas,information etc on how to eliminate vapor lock for good....I am not sure it matters , but I have a fuel cell and not a gas tank

thanx