[Dinosaur]

I am looking into upgrading my stock mechanical fuel pump on my '84 5.0 with a high vol. Carter unit. Strange thing is, the factory one has a small 1/4 line connected to the pressure side of the pump and seems to run back to the fuel tank. I have never seen this on a mechanical pump. It seems like this would "bleed" off fuel pressure and is not good for performance use.
What the heck is that line for? emissions or something?
any input appreciated.
Rick

 

[iwlbcnu]

That's it, it's the return line for the pump just like EFI. I just capped it off when I had the stock pump, was supposed to give a little more pressure.

 

[Dinosaur]

iwlbcnu-thanks, stock pump pretty weak?

Did you find the stock pump to be pretty limiting when you began with mods?
thanks,
Rick

 

[iwlbcnu]

I made 274rwhp w/ it. I had ported stock heads on a 306. I finally went electric just to be safe.