My old model FT 44 barrel is .787" and my new model SBH is .779". Ruger had to keep them within a consistent range or they'd have to custom fit the ejector rod housings for each different caliber barrel. That's why the .44 barrels make such great replacement barrels when converting FT 357s to 44 Spl.
I used the original 357 cyl pin, but it's very close. A SBH pin will be too long for the FT frame but easy enough to shorten on the back end. What I would do is put a slight crescent in the top side of the front end of the 357 pin, similar to the cut in the collar of the SBH pin.