I'm running a 300hp crate 360 magnum in my 91 power ram 150 4x4 short bed truck, I'm running a 30 gallon fuel tank, a off the shelf fuel pump from orielly auto parts, a quick fuel super street series 680cfm vacuum secondary carburetor.
Carburetor has a fuel pressure gauge on the line and it runs at 6 psi most of the time, sometimes it will drop to around 4.5 to 5.
Anyways when I first installed this carburetor I was only running one fuel filter, that was tied into the fuel hose after the fuel pump and before the carburetor, the fuel pressure gauge bounced around real bad, someone told me to put another fuel filter on the line that runs into the fuel pump just before the fuel pump and that should stop it, and it did.
I had someone tell me today that I should only run one fuel filter, that the filter between the carb and fuel pump isn't nessasary and that I'm causing a restriction by running two filters the way I am.
The one filter between the carb and fuel pump is a 3/8 Napa gold clear fuel filter, part number is 3003, the fuel filter between the tank and pump, that's installed real close before the pump is a 5/16 Napa gold clear fuel filter,Mozart number is 3002.
Is this an issue? I didn't think it was and in fact I thought it would be better to have two of the fuel filters since they are cheap little filters anyways that probly don't filter all that well.
I figured two would filter the fuel better then one, and I liked the idea of having the filter before the pump that way I'm not sucking any junk into the fuel pump, and I like the idea of the filter before the carb so I'm not sucking anything into the carb.

I don't see the need for 2 filters.

you're probably right but i too run 2 filters. one before the electric fuel pump and one before the carbs. both are NAPA gold 3/8.

i think the question was more about the 2 different sizes and you are fine with that too.

I was just wondering if I'm really causing that much of a restriction? I wouldn't think so, but then again I don't everything. I just figured a filter before the fuel pump and a filter before the carb was a good thing.

R-U happy with the performance of the truck?
If you are I would let sleeping dogs lie.

if your using a mech pump never put a filter on the suction side. i'd never put a filter/restriction on the suction side of an electrical pump unless it was something like a 100 micron or larger type strainer.

Look at what the factory did. Every car had a screen in the tank on the fuel sender unit and then another filter up between the fuel pump and carb. As was said the filter on the suction side should be of a certain micron size as to not cause any restrictions on the suction side that can overwork and damage the pump. All the Mopars had a fuel filter between the fuel pump and carb and they all had the screen in the tank. So if you use a filter before the pump it needs to be of a certain micron which I dont remember at this time what that is. Many of us have run a filter before the pump as I see many guys run the Fram cartrige filter before the pump when they use an electric fuel pump and run fine but they say its not the right size micron to run the Fram cartrige filter before the pump as that one should be after the electric pump. Ron

The clear palstic covered fuel filters burn a lot easier than the full metal covered ones do I use to run two of them on my old M.W. stocker, NHRA tech outlawed all plastic covered fuel filters under the hood on any of its cars participating at any other thier races back in the mid to late 1970s I would run one filter only other than what was stock in the fuel tank from the factory with a mechanicl pump The paper element fuel filters are 10 micron so that is a very fine filter I would run it like stock like Ron has suggested, better to push the fuel through it than to suck it through it

unless the line ID is too small (not likely unless a high HP app which ain't the case here) so right now if you have enough psi at the carb INLET then you are good. What Lewt said, I'd want no filter before a mech pump and I would want a 100 micron before an electric pump then in either case a 10 micron filter right at the carb inlet. In your case a parts house Wix filter before the carb is fine (mech/not elect pump correct?) If elec & mech then the 100 micron before the elec is a good idea to protect it. You'd be surprised at the amount of crud that makes it thru gas stn pump filters

Yes I'm running a mechanical fuel pump, I just replaced both filters today, so I guess I'll run the filter before the pump untill it gets dirty, then I just won't put another one if its not a good idea.
I did notice the filter before the pump was a lot dirtier then the filter between the carb and pump. So having that filter there did prevent a lot of crud from being sucked into the fuel pump.

In your case with crud getting into the smaller filter I would buy and install a cleanable (#6AN or larger)in line filter that is rated at 80 to 100 microns Summits offers thier own brand as well as a bunch of other brands that will fit your deal real well Make sure and get it away from the heat of the headers or exhaust so it doesn't turn into a heat sump and preheta the fuel going into the pump