Ok I have a 84 camaro with the 305 in it. I put a brand new fuel pump on it and it worked fine for a little while.

I ended up getting gas in my oil so I changed my oil. I go to start it up, and no fuel is coming from the pump.

This new pump doesn't a return line hookup like the old one did, so is that why it's not working? Why did it work before then?

If I put compresse in into the return line and pressurize the tank, then its able to start up and run fine.

I'm pretty lost and dumbfounded here