I'm considering plumbing my fuel system in braided with an fittings. My question is on the Edelbrock 1407 what is the size of the fuel inlet, is it removable.Could I take out the brass barb fitting and screw in a aeroquip 90.

 

It comes with the standard 3/8".

yes you can change the fittings to whatever you like. The carb body is aluminum and easy to drill and re-tap for any size fitting. Actually it is a common mod for me to tap the driver-side to make it dual feed.
I can get quite a bit more fuel into one with only a couple of mods, but the final restriction is the needle/seat. I am working on a custom one with much higher capability.

ODB

 

I'm getting ready to order the parts for the same project, that's 3/8" NPT right? The inlet and outlet fittings on the stock mechanical pump are -6 AN and the return is -4 AN?

It's been a while since I had to mess with the fuel system. I'd go out to the car and check but I don't feel like splashing gas everywhere today.

 

No, that doesn't sound right, it's pipe thread on the pump, isn't it? 1/4 and 1/8 NPT? Am I just arguing with myself?