Need intake coolant fitting

[DeathProofCuda]

NPT fittings can be a bit confusing.  You have to remember that the sizes are based on pipe sizes and that pipe sizes are specified by their inner diameter, not their outer diameter.  That's how you get a 1/2" pipe that has an OD of 0.84".

For the fittings in my photo, the 1/4" NPT one is sized for a 1/2" (ID) heater hose.  The 3/8" NPT fitting is sized for a 5/8" ID hose.

Seems like the fitting you found at Summit would be the ticket

[Burdar]

The factory fitting from my Challenger is in the middle.  Is this what you need?  I got a replacement at my local parts store.  It doesn't look the same but it works.  After I bought the replacement, I found out that Mega Parts sells the factory correct part.  I think it's 5/8 pipe thread and reduces to fit a 1/2" heater hose.  The fitting on the left in the picture is out of the HELP line at the parts store.

Edit:  Yep, here it is.  You can get a replacement that reduces to 1/2" at your local parts store but I don't have the part # any more.  The reducer fitting isn't in the HELP line.
http://www.megapartsusa.com/proddetail.asp?prod=132%2DHC010

[kawahonda]

Wow...I am shocked you found a 5/8 NPT fitting. Not only that, but you found one that is slotted and that looks stock.

It sounds like I'm actually a 3/8" NPT because I didn't understand NPT pipe threading, and still don't. LOL

Hopefully this thread will help others in the future.

For reference, the LD340 uses 3/8" NPT for the bypass.

What's included in the small block 340 kit from the venders is probably a 1/4" NPT. I cannot tell you if that is stock or not, but it doesn't fit the LD340.

[DeathProofCuda]

The fitting that Burdar linked is not 5/8 NPT.  There is no such thing.  NPT fittings jump from 1/2" to 3/4".  As the link states, it is 5/8" hole size, which means it is actually 3/8" NPT.  Yes, it is confusing. 

Bottom line is that either the part you found at Summit or the one that Burdar linked looks like it should work for you.

Here is a link to a chart showing NPT pipe sizes:

https://www.engineeringtoolbox.com/npt-national-pipe-taper-threads-d_750.html

[73440]

Quote from @DeathProofCuda ,  Here is a link to a chart showing NPT pipe sizes:

https://www.engineeringtoolbox.com/npt-national-pipe-taper-threads-d_750.html

@DeathProofCuda , that's a good website, used before , lotta info.

[YellowThumper]

NPT (National pipe taper) diameter callouts are for the ID. Not the thread. That would be huge. IIRC they should be 3/8 NPT into manifold. Thread od will be around 5/8 or so. This fitting can then have the 1/2 or even 5/8 OD barb to hold 1/2 or 5/8 ID heater hose.

-edit- lol I now read the previous same answers after I wrote reply

[DeathProofCuda]

NPT (National pipe taper) diameter callouts are for the ID. Not the thread. That would be huge. IIRC they should be 3/8 NPT into manifold. Thread od will be around 5/8 or so. This fitting can then have the 1/2 or even 5/8 OD barb to hold 1/2 or 5/8 ID heater hose.

-edit- lol I now read the previous same answers after I wrote reply

Hey, at least we're all on the same page now!