Boilermaker1

iTrader: (16)

I know its a -6, but there's 2 possibilities.... -6 to a 1/4NPT or -6 to 3/8 NPT. While I plan on hacking the NPT threads off and welding the nut straight to the rail, the hole inside the 3/8 one (and the nut on it) will be substantially larger.... thus require a bigger hole to be drilled in the rail. I cant imagine that much gas going back through, but who knows.
So.... 3/8 or 1/4" which is the better option. And are you guys using a steel fitting, or a stainless one. I'm assuming under the zinc coating, its just plain old steel but with all the low grade stainless things they've snuck in.... who knows.

tfnaaf

iTrader: (2)

I forget what size mine is. But your saying that you currently have a NPT nut welded on now? As for the material i used just a standard steel fitting and had it tig welded on. After the new one is welded on use a straight edge to make sure it didnt warp too much. I had to flex mine just a bit to make it flat again.

XSRCivic

iTrader: (19)

This is basically what was welded to my rail (SLP return kit) and essentially what you will end up with once you are done hacking the threads. I'd go 3/8 just because its bigger and it will still fit. Not that 1/4 would restrict flow but going bigger doesnt hurt. I have no clue what kind of material its made of though, my guess is SS.

Boilermaker1

iTrader: (16)

No, nothing is welded on... but I was just gonna get a NPT/AN adapter and cut the NPT threads off. I forgot about the damn thing warping... I'll have to bolt it to something so it stays.


Thinking about it though... the size of the hole doesnt necessarily matter, as long as its bigger than the feed hole, which either will be, the regulator will hold it at 43psi or whatever and that line is gonna "back up" persay to maintain the pressure. So as long as the outflow is capable of being more than in, it will work.
I can see the benefit of the bigger hole though... the pump wants to push with as little restriction as possible. the bigger the hole in that fitting, the more it can push, and the cooler the pump stays.