npt size

[A-2 ace]

Does anyone know what the npt tread size is on the radiator oil cooler lines

 

[SAATR]

If it's a Vortec, M20x1.5 o-ring face.

 

[A-2 ace]

its a tbi.. i want to swap out the crap lines to an

 

[Schurkey]

The info is on this site if you'd search. As said, it's NOT NPT.

I remember folks using Dash 6 hose; which as far as I'm concerned is too damned small. The metal tubes on the end of my original hoses is 1/2"; theoretically equivalent to Dash 8.

Seems to me that there were problems finding fittings that had the correct thread for the radiator, AND the Dash 8, 37 degree flare.

 

[A-2 ace]

they make male npt to -8an for cooler lines i just dont want to buy the wrong thing..

 

[df2x4]

Like SAATR said, it's not NPT. It's M20x1.5 with an o-ring seal. Vibrant Performance makes M20x1.5 to AN adapters but they don't have the correct o-ring seal, I've looked and never found a correct part for this.

EDIT - As mentioned this is for the Vortec trucks, not sure if the TBI trucks use the same size fittings or not.

 

[454cid]

Like SAATR said, it's not NPT. It's M20x1.5 with an o-ring seal. Vibrant Performance makes M20x1.5 to AN adapters but they don't have the correct o-ring seal, I've looked and never found a correct part for this.

That's probably because the o-ring goes on the line, on the original hose, and not the fitting/connector. It would be handy to know what that is called. It's more than just a thread size and pitch.

 

[Schurkey]

The info is on this site if you'd search. As said, it's NOT NPT.

I remember folks using Dash 6 hose; which as far as I'm concerned is too damned small. The metal tubes on the end of my original hoses is 1/2"; theoretically equivalent to Dash 8.

Seems to me that there were problems finding fittings that had the correct thread for the radiator, AND the Dash 8, 37 degree flare.

https://www.gmt400.com/threads/how-to-install-an-oil-cooler-lines.30454/