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I'm looking to stick a t-bridge on one of my builds. I usually radius to 12" and the T-Bridge is 14". I think that's about a .006" difference. My gut feeling is that this won't be enough for anyone to care. I cut my nut precisely, but I certainly don't set my action precisely and definitely not to within .006". I thought I'd try to tap some experience, though, as I don't think I have any experience at all with a mismatched neck/bridge radius.

The 14 radius is a little flatter, which means that if you set your two outside strings the same height off the fretboard, the middle strings will be slightly closer to the fretboard by a small amount. I used my radius gauges to check how much closer, by tracing out the 12, and measuring how far away the 14 was from the line at the width of 2 and 1/16th inches at the saddle.
I measured 1/64th of an inch, which means that with the neck perfectly straight, the middle strings will be approximately 128th of an inch closer to the fretboard than the outer strings at the 12th fret. I would probably start with the outer strings even to the fretboard, lower the treble side 1/128th, and raise the bass side 1/128th of an inch (approximately half of 1/64th), that will make the first four strings about the same height from the fretboard, with the remaining two bass strings a hair higher, and you should be fine. Your accuracy will depend on the tools you use, I use a six inch steel rule with 64th inch increments and get very consistent results (despite my use of the words "about" and "approximately") 'cuz that's what I'm used to.

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