Exhaust Manifold Hose Barbs

Without checking the fittings on a 3/4 NPT pipe gage there is no way to know if the fitting has the right pitch diameter. The same goes for the casting. Yes it is spelled "gage",   I worked as a Tool and Die Maker in gages for 30+ years.

Those little China men don't always get things just right!!

I use "Locktite" brand teflon pipe sealer on everything pipe. Teflon tape would work, as any that gets loose will just flush out the exhaust. Never on fuel fittings or oil fittings.
Just my $.02

"buy it now" 3/4 tap on ebay
Brass should not need any type of thread sealant with good threads since it's relatively soft. IA sealant won't hurt but I prefer a paste over tape. Rectorseal Tru-Blu is great on pipe threads.

Chris,
You mentioned the threads "appear to be fine" and "aren't as sharp as they were". You can't tell the condition looking at them without an optical comparator! A pipe thread is a spiral grove so if the threads are distorted, the spiral grove is a passageway for leakage. To stop the leak, I feel you are back to square 1 getting new elbows and chasing the manifolds as originally suggested. Sorry.

I agree, but I think the fitting was too larger to begin with. I tried to screw it into a female fitting at Home Depot and it wouldn't go in. I called Skidim and epower and they both suggested the threads were correct, but I disagree. I unscrewed the first new barb that I wrenched in and the threads after the fact matched the threads of the old fitting from the first pic and it screwed back into the manifold with no problem so the threads appear to be fine. They just aren't as sharp as they were when I received them. I thought the female end in the manifold was built up with corrosion over the years, but I cleaned the female threads with a Dremel mini wire wheel and they did not appear to be corroded... It has been one of those "simple modifications" that turned into a major pain in the arse!

I got about 2/3 of the threads on, but can go further if it becomes a problem. I got a very slight drip out of one of them so will probably pull it and wrap with Teflon tape or maybe try the gasket sealer...

Well, it didn't feel right cranking the barbs in there with a wrench like that. They squeeled the whole way as it milled down the brass threads with every turn, but it worked and it's water tight. Thanks!

The manifold castings are the same, the brass barbs will work (I've converted some). Clean the threads with a wire brush and then install with a wrench.