Steve;

Jets are Jets and metering needles are metering needles. The terms should not be used interchangably, because they are two seperate and different items.

As other poster has stated: Needle type is stamped onto end which is held in dashpot, but if liberties have been taken with one needle I wouldn't trust the other...if your needles are a different length, that's definately not right!...although the very end of the metering needle is only metering at high load/high RPM, if the end if the MN has been shortened, that "expert" may have done who-knows-what with the shape of the rest of the needle...

My advice: Get a new pair of (not necessarily new), but otherwise unmolested MNs.

Cheers