Put the pump in and now has extended crank after sitting a few minutes.
Seems obvious the fuel pressure is bleeding off. Anybody have this issue?
It is an '04 1/2 ton Chevy with the returnless fuel system.

 

Sounds to me like you might have to drop the tank and take another look at the installation. I did mine per the Magnacharger 04 instructions and it came out perfectly. You can look at their instruction manual online and you might see the problem if there is one. I know that sucks to think about dropping the tank but I think it's your only solution.

If you didn't mess with the fuel rails or any other connectors it narrows it down a lot.

 

the clear accordian tube has caused problems for some.