Here Amazon product
I’d love to hate Amazon, but there ability to connect you to obscure things with non-traditional sizes is hard to beat. I believe I checked McMaster Carr but they didn’t have the BSPT versions iirc.
I didn’t have to retap the holes, the 1/8” BSPT fit. I used thread sealant. My fuel filter housing is new OEM Toyota (glass bowl is used per this thread), don’t know if the threads changed over the years. I also used these fittings in my original early (‘63) fuel pump - it has the prime lever - so I’m guessing these threads have been the same for a long time.
If I ever dump the dual carb/offenhauser setup and return to the single OEM carb (and replacement manifold) I'll run original fuel lines as best as possible. Right now I could go original from tank to filter, and filter to pump. Still have the fittings for the filter and pump. After that it gets custom because of the dual carb setup. So I got lazy since I'm not chasing OEM too much.