What is the thread size of the fuel rail where the schrader valve is? Looks like -4AN, can anyone confirm this? I need to get a fitting to attach the fuel pressure sending unit to the fuel rail.

 

-4an or #4 hydraulic fitting.

 

need something like this
http://brennaninc.com/ProductDisplay...tem=6506-04-02

 

search

EAR-916104ERL
and
FRA-491001

on summit

 

-4AN it is, thanks!

 

The the schrader valve is -4an?

 

how would this work?? wouldnt you need some kind of special fitting to push in the schreador valve?? ive been wondering if you could run a fuel pressure gauge off the test port..

 

I have the valve removed in my test post. Im going to swap to an aftermarket fpr so I need to know the size of the schrader

 

There is a plastic cap that screws onto the fuel rail over the schrader valve. I believe it's threaded to -4AN, at least it was on my Z28. The schrader valve inside can be removed easily so you can get a pressure reading.

Here is a thread I made 7 years ago, but it was for my Z28, which I'm guessing is the same thread, but different location, as my '01 Silverado:
https://ls1tech.com/forums/fueling-i...ender-pic.html

And another one:
https://ls1tech.com/forums/fueling-i...read-size.html

 

Metco makes the adapter, but putting two together is cheaper.

GM Fuel Rail Adapter, Fuel System Components: Metco Motorsports