I have an 84 Z-28 and I am having a vapor lock issue. It has a 350 bored .30 over and a mild cam. it has a mechanical fuel pump. the car is vapor locking on me and i cannot figure out how to fix it. it doesnt happen all the time but it will every once in a while. the little glass fuel filter was showing nothing but bubbles!! Its pretty bad and any input would be nice.

 

What is the fuel pressure

 

The factory setup uses a return fuel pump. That right there should have the problem fixed.

If that doesn't your next step would be to add a small spacer between the carb and intake.

 

Do away with the mechanical fuel pump and install an electric low pressure in line fuel pump

 

You can get a fuel pump block off plate to replace your pump

 

I'm assuming you have a carb because of the mechanical fuel pump, yes?

You need to confirm two things before doing anything else.

1. Fuel pump pressure - should be around 8psi or thereabouts.
2. Fuel pump volume - should fill a pint can in about 30 seconds at idle.

Check your service manual for the actual test specs.