You should give the bike's mods or no one can say for sure. I can tell you TBS needles are long and will require shims just to get anything more than stock out of them on some if not all twins. Un-shimmed Thruxtons work almost exactly the same for my 05 speedy as TBS with 3-1/2 shims. (2 regular .5 mm shims and a washer thats about the thickness of 1-1/2 of a .5 shim) the only slight difference I can tell is the thruxtons seem to have a tad more off the line but a bit less than the shimmed TBS in mid range roll-ons. if you're intake is less open than mine i'd go with TBS and a couple shims. The thruxtons were almost too rich for my bike with UNI filter, no snorkel, and bottom drilled. But if yours equally opened up then you can try thruxtons. But if they're too rich you can't back em down like you can with shimed TBS.
