ok im switching from tbi to carb and i was wondering if i have to take the fuel pump out of the tank or can i just disconnect power to it. i already have the carb fuel pump and i know that i will have to drop the diff to get to the gas tank and then if i do have to pull the tbi fuel pump will i have to do anything special to make the carb fuel pump work with the stock lines? thank Ty.

 

are you dead set on using the pump on the block? is the tbi pump bad? you could just install a regulater and not drop the tank. if you are going to drop the tank just install a pick up screen in place of the old pump.

 

after you saying that im not set on useing the carb fuel pump, i just thought that if i ran a car i would need the pump for the block, but no the tbi fuel pump is good, so all i will need to run the tbi fuel pump is get a fuel pressure regulator?

 

yes sir a return style regulater. go to the home page and click on tech articles. it gives the part numbers of some good ones. make sure it is a return style.

 

sweet well that just saved me a lot of time from pulling the diff and the tank, thanks A LOT!

 

I had the same question, ditto the thanks!

 

What if the in tank pump was replaced with a pick up screen? Would you still need a return style regulator?

 

Then you would need an external pump. I'm using stock fuel pump and the Mallory 4309 with my Holley 80670.

 

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Hey, just curious where did you mount the mallory and do you have a regulator before the mallory as well as after? I have a stock tpi high pressure pump and when cranked down to 6 psi it just doesn't flow enough for my 383.. I was planning on buying a 255lph pump but it doesn't flow much at low psi for my holley.

 

Ditto above, I believe due to the design of the sending unit. Not sure if you could just block off the return if you are still using the in-tank pump, but I've found a new external pump is less expensive than the regulator.

 

You could have kept the stock pump and just used an adjustable fuel pressure regulator. but since you already have the pump you can just get a pick-up and fuel lines from a carbed third gen tank at the junk yard and that should work just fine.

 

Not if you used a pump with an internal bypass, but there are still a lot of good reasons to use a return regulator.

 

i bought a holley blue pump. i am still using the 4309 mallory but the holley pump comes with its own regulator.

 

Yeah, that's what I'm running right now, problem is I'm not getting enough flow from my stock tpi pump. It's a new pump, but doesn't flow enough. I am thinking of a 255lph pump, but because they high flow at high psi, i'm not sure it'll deliver enough when regulated to 6psi for my holley? Has anyone run a cammed 383 with a 255lph pump?

 

The Mallory 4309 is the pressure regulator. I have mine mounted on the driver's side strut well, right above the fuel lines. You shouldn't be having any flow issues with the regulator, it is really open on the inside. The only restrictions that I can think of right now might be your fuel line diameter, other than that maybe fuel filters that haven't been replaced.

 

I tried that for a while, but I was having problems with mine so I spent the money on the regulator and cleaned up the install.

 

So are you using the stock tbi pump? I had a 91 RS Vert with a ZZ383 and stock pump and it never ran dry, I just can't fathom replacing a stock pump where a stock pump already is..?

 

Yeah I saw no sense in dropping the tank if I didn't have to. Besides, why replace a stock pump if it still work fine and I just replaced the fuel filter?