Owned my car for 12 yrs, equipped with the Holley repro 6pack for 440 (69-70 version). So it has been running trouble free till now. Since last summer, the center carb (4144-1) is leaking at the pump diaphragm area. I have changed out the diaphragm (GFLT type) 3 times now and it still leaks. I installed a new Accelerator pump housing (30cc) since the original one was a bit warped. It still leaks at the accelerator pump area. Actually see slow dripping at center of pump housing. So I think maybe its leaking at the bowl gasket area to the pump area. So I changed out bowl gasket, same result. Tried to get a mirror to see exactly where its coming from and its too difficult. What should I be looking for? Im stumped. Im thinking the bowl maybe getting porous somewhere, but don't know. Next stop is to replace the bowl, but Holley says they do not stock new bowls for this carb. Anyone know where to get a new replacement bowl? Worried about a used one having same issue. Any tips would be great!
Thanks all.

been thru this. mine was a warped carb body causing the leak.

I've had faulty diaphrams that leaked where the metal button meets the rubber. Maybe try a different diaphragm source.

Pull the center carb off and use a fine cut mill file to see if the pump housing and the fuel bowl have high spots on them
Been there done that more than once to fix them mystery leaks
Take your time and don't go hog wild on filing them
Let us know what you find

The alcohol in the fuel is hard on rubber parts. You can use Emory cloth on a flat surface to knock down the high spots. Try using the Superformance gaskets on the bowl, metering block and accelerator pump after you get the surfaces flat. Or at least use the non-stick Holley gaskets.

I usually recheck the torque on the carbs a few times and often find a screw or two that needs a bit more tightening after a few heat cycles.

The blue gaskets and diaphragms are all Holley parts. I did check for warpage with a straight edge and I replaced the pump housing. The old housing was warped. Please submit any other tips. Im going to have to remove center carb again. Please keep submitting your tips.

You can fix the high spots in the old pump housing with the file, same thing on checking the float bowl
Another thingt o make sure of is that your pump housing screws are to long and bottoming out before securing the pump housing to the float bowl

I recently replaced the center carb on my dad's 440-6 road runner due to a leakage issue. Holley had a bad batch of carb castings in the late 2000s and replaced it no questions asked when I gave them the date code and list number off of it. The thing looked like it was falling apart.
His carbs were all bought new as a package around 2007 or 2008 I believe.

I see what you are saying. Will have to check that out. My car was restored in 2003, so I don't know if these carbs are that old. But definitely something to keep in mind.

Google on zinc plague !