The new geroter pump in my custom D100's fresh 383 quit pumping & my body guy can't get it out of the shop,
so I'm wondering if its forward of the tank position instead of behind it is what's causing it?? And I just realized I got
their $430 comp pump instead of the $230 one that's in my W100! Hope I don't have to reposition the pump since the
tank is at the rear of the frame. Thanks for any advice..

Imo, the pump is waaaay too far away from the tank, and too high up as well.

If it’s the 250 pump, it really needs to be used with at least a bypass return return system at the pump.

The best solution for where that tank is, is to use a submersible in take pump.

Thank's Dwayne & I'll check with Summit here to see if they have an in tank pump that'll work with this tank &
isn't difficult to install. I wonder if the in tank pump has its own filter or if I can use the existing filter. If the in tank
pump is a difficult install, do you think the Mallory or Holley street geroter pump down just in front of the tank would
work?

Most of that style of pumps aren’t very happy lifting fuel up and out of a deep tank.
They’re much better at pushing it out.

There are a few vendors that would have in tank pumps that would be a better option.

Walbro makes quite a few varieties of them.

I'm not sure I can see exactly what you have going on there but it looks to me like you should put a bung on the lower corner of the tank so you pull out of the bottom of the tank. You should also swap the positions of the pump and filter. I assume you are pulling out of the tank and then pushing thru the filter? If you are pulling thru the filter then you'll always have problems.

I would think that it needs to be gravity feed on the inlet. Doesn't look like it would. For it to stay primed under usage/slosh and rely on siphon feed, I would think you would need good head pressure which would require lowering the pump and filter. I also would make the drop/inlet line as big as possible.

Thanks guys for your help & to save $$ from doing the in tank pump conversion, I'll try what the Mallory tech advised &
because he said the pump will work if I reposition it between the tank & filter & I shouldn't have to reposition the tank
inlet & outlets to the bottom of the tank. SO, we'll soon see if it works & hope my friend can get to it soon.
Originally, I wanted to put the tank where the battery is now & then I could've put the pump behind it, but "saving money" to work with the tank I had was the wrong choice for sure! If I wasn't going to sell the D100, I'd get a custom fuel cell that fits in the middle & it'd look much better from the rear.

Is that fuel filter a Fram or a chinese clone of the Fram? If so does it have a paper element in it? If so change it to a 100 micron or larger element.
The paper fuel filter elements are all 10 micron or smaller which really limits the fuel flow through them when sucking the fuel from the tank to the pump, I learned that lesson the hard way once
Install it in front of pump going to the carb or fuel pressure regulator and use a 100 micron or larger filter between the pump and tank

Thanks Cab & I can't remember the manufacturer but think it was a Summit brand I got about 17 yrs ago for a 69 Charger R/T project I was doing & kept it brand new in the box till 2 mos ago. I'll sure check the filter & maybe just replace it whth a 100 micron filter.
** New Info:
Cab, it is a Summit brand, made in China with paper 10 micron filter, so a new filter and moving the pump will be what we do first. What you said was a little confusing about where the filter should go:
"..Install it in front of pump going to the carb or fuel pressure regulator and use a 100 micron or larger filter between the pump and tank [/quote]"...
So should the pump be in front of the filter or behind it?
Thanks for the info!

Relocate that filter so it is in between the pump and carb or pressure regulator.
Not that type fuel filter between the tank and the pump, use a filter that is big enough to flow a lot of fuel with a 100 micron or bigger element between the tank and the pump

Cab, I think I'll put the pump where the filter is now since they're about the same size & mounting setup & I'm thinking of
putting this Holley 100 micro scree filter where the exixting pump is now. Filter's $80 so that's a lot less than a new pump.

All the stuff you have already will work but the location of the parts is the problem. That pump needs to be gravity fed and it will work great in your application. An in tank pump would work the best for your rod the way you have it plumped and your type of fuel call.
You could use a check valve to keep fuel in the lines and pump but a gravity feed to a g-rotor is still the best choice if you don't go with an in-tank pump like the Aeromotive Stealth pump and filter combo
Gus